diff --git a/source/common.h b/source/common.h
index 545220b..6f40f7d 100644
--- a/source/common.h
+++ b/source/common.h
@@ -25,6 +25,9 @@ inline constexpr std::nullopt_t None{std::nullopt};
 template<typename T>
 using Option = std::optional<T>;
 
+template<typename... Ts>
+using Variant = std::variant<Ts...>;
+
 struct Error : public std::runtime_error {
 	using std::runtime_error::runtime_error;
 };
@@ -122,17 +125,20 @@ static inline QDebug operator<<(QDebug debug, std::string const &t) {
 	return debug;
 }
 
-template<typename T>
-static inline QDebug operator<<(QDebug debug, std::unique_ptr<T> const &t) {
-	debug << *t;
-	return debug;
-}
-
 template<typename T0, typename... Ts>
-static inline QDebug operator<<(QDebug debug,
-                                std::variant<T0, Ts...> const &t) {
+static inline QDebug operator<<(QDebug debug, Variant<T0, Ts...> const &t) {
 	std::visit([&](auto &&arg) {debug << arg;}, t);
 	return debug;
 }
 
+template<typename T>
+static inline QDebug operator<<(QDebug debug, Option<T> const &t) {
+	if(t) {
+		debug << *t;
+	} else {
+		debug << "None";
+	}
+	return debug;
+}
+
 // EOF
diff --git a/source/quam/archive.cc b/source/quam/archive.cc
index 0cb0e8f..5dcca3a 100644
--- a/source/quam/archive.cc
+++ b/source/quam/archive.cc
@@ -6,148 +6,150 @@
 #include <QIcon>
 
 namespace Arc {
-
-Option<ArchiveType> getArchiveType(std::istream &st) noexcept {
-	try {
-		auto pos = st.tellg();
-		auto magic = readBytes<4>(st);
-		st.seekg(pos);
-		if(magic == std::array{'P', 'A', 'C', 'K'}) {return ArcPack;}
-		if(magic == std::array{'W', 'A', 'D', '2'}) {return ArcWad2;}
-	} catch(...) {
+	Option<ArcType> getArchiveType(std::istream &st) noexcept {
+		try {
+			auto pos = st.tellg();
+			auto magic = readBytes<4>(st);
+			st.seekg(pos);
+			if(magic == std::array{'P', 'A', 'C', 'K'}) {return ArcType::Pack;}
+			if(magic == std::array{'W', 'A', 'D', '2'}) {return ArcType::Wad2;}
+		} catch(...) {
+		}
+		return None;
 	}
-	return None;
-}
 
-Dir readArchive(std::istream &st) {
-	switch(auto v = getArchiveType(st);
-	       v.has_value() ? *v : throw FileFormatError("not an archive")) {
-		case ArcPack: return readPack(st);
-		case ArcWad2: return readWad2(st);
+	Dir readArchive(std::istream &st) {
+		switch(auto v = getArchiveType(st);
+		       v.has_value() ? *v : throw FileFormatError("not an archive")) {
+			case ArcType::Pack: return readPack(st);
+			case ArcType::Wad2: return readWad2(st);
+		}
 	}
-}
 
-Dir::iterator Dir::findNode(std::string const &name) {
-	return std::find_if(begin(), end(), [&name](Node const &node) {
-		return node.name == name;
-	});
-}
+	Node *Dir::findNode(std::string const &name) {
+		auto it = std::find_if(begin(), end(), [&name](Node &node) {
+			return node.name == name;
+		});
+		return it != end() ? &*it : nullptr;
+	}
 
-Node::Node(Dir &&f, std::string &&n, FileType t) :
-	super_type(std::move(f)),
-	name(std::move(n)),
-	type(t)
-{
-}
+	Node::Node(Dir &&f, std::string &&n, FileType t) :
+		superType(std::move(f)),
+		name(std::move(n)),
+		type(t)
+	{
+	}
 
-Node::Node(File &&f, std::string &&n, FileType t) :
-	super_type(std::move(f)),
-	name(std::move(n)),
-	type(t)
-{
-}
+	Node::Node(File &&f, std::string &&n, FileType t) :
+		superType(std::move(f)),
+		name(std::move(n)),
+		type(t)
+	{
+	}
 
-Model::Model(QObject *parent) :
-	QAbstractItemModel{parent},
-	m_dir{nullptr}
-{
-}
+	Model::Model(QObject *parent) :
+		QAbstractItemModel{parent},
+		m_dir{nullptr}
+	{
+	}
 
-Model::~Model() {
-}
+	Model::~Model() {
+	}
 
-QVariant Model::data(QModelIndex const &index, int role) const {
-	if(!index.isValid()) {
+	QVariant Model::data(QModelIndex const &index, int role) const {
+		if(!index.isValid()) {
+			return QVariant{};
+		}
+
+		auto node = static_cast<Node *>(index.internalPointer());
+		auto col  = Column(index.column());
+
+		switch(role) {
+			case Qt::DecorationRole:
+				if(col == Column::Name) {
+					auto icon =
+						std::holds_alternative<Dir>(*node) ? "folder"
+						                                   : "text-x-generic";
+					return QVariant{QIcon::fromTheme(icon)};
+				}
+				break;
+			case Qt::DisplayRole:
+				switch(col) {
+					case Column::Size:
+						if(auto file = std::get_if<File>(node)) {
+							return QVariant{QString::number(file->size())};
+						}
+						break;
+					case Column::Type:
+						return QVariant{tr(enumToString(node->type))};
+					case Column::Name:
+						return QVariant{tr(node->name.data())};
+				}
+			case Qt::UserRole:
+				return QVariant::fromValue(static_cast<void *>(node));
+			default:
+				break;
+		}
 		return QVariant{};
 	}
 
-	auto node = static_cast<Node const *>(index.internalPointer());
-
-	switch(role) {
-		case Qt::DecorationRole:
-			if(index.column() == ColumnName) {
-				auto icon =
-					std::holds_alternative<Dir>(*node) ? "folder"
-					                                      : "text-x-generic";
-				return QVariant{QIcon::fromTheme(icon)};
-			}
-			break;
-		case Qt::DisplayRole:
-			switch(index.column()) {
-				case ColumnSize:
-					if(auto file = std::get_if<File>(node)) {
-						return QVariant{QString::number(file->size())};
-					}
-					break;
-				case ColumnType:
-					return QVariant{tr(enumToString(node->type))};
-				case ColumnName:
-					return QVariant{tr(node->name.data())};
-			}
-		default:
-			break;
-	}
-	return QVariant{};
-}
-
-Qt::ItemFlags Model::flags(QModelIndex const &index) const {
-	if(!index.isValid()) {
-		return Qt::NoItemFlags;
-	} else {
-		return Qt::ItemIsSelectable  |
-		       Qt::ItemIsDragEnabled |
-		       Qt::ItemIsEnabled     |
-		       Qt::ItemNeverHasChildren;
-	}
-}
-
-QVariant Model::headerData(int section,
-                           Qt::Orientation orientation,
-                           int role) const {
-	if(orientation == Qt::Horizontal && role == Qt::DisplayRole) {
-		switch(section) {
-			case ColumnSize: return QVariant{tr("Size")};
-			case ColumnType: return QVariant{tr("Type")};
-			case ColumnName: return QVariant{tr("Name")};
+	Qt::ItemFlags Model::flags(QModelIndex const &index) const {
+		if(!index.isValid()) {
+			return Qt::NoItemFlags;
+		} else {
+			return Qt::ItemIsSelectable  |
+			        Qt::ItemIsDragEnabled |
+			        Qt::ItemIsEnabled     |
+			        Qt::ItemNeverHasChildren;
 		}
 	}
-	return QVariant{};
-}
 
-QModelIndex Model::index(int row, int col, QModelIndex const &parent) const {
-	if(!m_dir || !hasIndex(row, col, parent) || row > m_dir->size()) {
+	QVariant Model::headerData(int section,
+	                           Qt::Orientation ori,
+	                           int role) const {
+		if(ori == Qt::Horizontal && role == Qt::DisplayRole) {
+			switch(Column(section)) {
+				case Column::Size: return QVariant{tr("Size")};
+				case Column::Type: return QVariant{tr("Type")};
+				case Column::Name: return QVariant{tr("Name")};
+			}
+		}
+		return QVariant{};
+	}
+
+	QModelIndex Model::index(int row,
+	                         int col,
+	                         QModelIndex const &parent) const {
+		if(!m_dir || !hasIndex(row, col, parent) || row > m_dir->size()) {
+			return QModelIndex{};
+		} else {
+			return createIndex(row, col, &m_dir->at(row));
+		}
+	}
+
+	QModelIndex Model::parent(QModelIndex const &) const {
 		return QModelIndex{};
-	} else {
-		// despite index data being const, this function does not take a const
-		// pointer, which is very annoying!
-		return createIndex(row, col, const_cast<Node *>(&m_dir->at(row)));
 	}
-}
 
-QModelIndex Model::parent(QModelIndex const &) const {
-	return QModelIndex{};
-}
-
-int Model::rowCount(QModelIndex const &) const {
-	return m_dir ? m_dir->size() : 0;
-}
-
-int Model::columnCount(QModelIndex const &) const {
-	return enumMax<Column>();
-}
-
-Dir *Model::dir() const {
-	return m_dir;
-}
-
-void Model::setDir(Dir *dir) {
-	if(dir != m_dir) {
-		m_dir = dir;
-		emit layoutChanged();
-		emit dirChanged(dir);
+	int Model::rowCount(QModelIndex const &) const {
+		return m_dir ? m_dir->size() : 0;
 	}
-}
 
+	int Model::columnCount(QModelIndex const &) const {
+		return enumMax<Column>();
+	}
+
+	Dir *Model::dir() const {
+		return m_dir;
+	}
+
+	void Model::setDir(Dir *dir) {
+		if(dir != m_dir) {
+			m_dir = dir;
+			emit layoutChanged();
+			emit dirChanged(dir);
+		}
+	}
 }
 
 // EOF
diff --git a/source/quam/archive.h b/source/quam/archive.h
index c4eeb9a..2ad12b6 100644
--- a/source/quam/archive.h
+++ b/source/quam/archive.h
@@ -12,10 +12,10 @@ namespace Arc {
 	struct Node;
 	struct Dir;
 
-	enum Column {
-		ColumnSize,
-		ColumnType,
-		ColumnName,
+	enum class Column {
+		Size,
+		Type,
+		Name,
 	};
 	Q_ENUM_NS(Column)
 
@@ -30,28 +30,28 @@ namespace Arc {
 	};
 	Q_ENUM_NS(FileType)
 
-	enum ArchiveType {
-		ArcPack,
-		ArcWad2,
+	enum class ArcType {
+		Pack,
+		Wad2,
 	};
-	Q_ENUM_NS(ArchiveType)
+	Q_ENUM_NS(ArcType)
 
-	Option<ArchiveType> getArchiveType(std::istream &st) noexcept;
+	Option<ArcType> getArchiveType(std::istream &st) noexcept;
 
 	Dir readArchive(std::istream &st);
 
 	struct Dir : public std::vector<Node> {
 		using std::vector<Node>::vector;
 
-		Dir::iterator findNode(std::string const &name);
+		Node *findNode(std::string const &name);
 	};
 
 	struct File : public QByteArray {
 		using QByteArray::QByteArray;
 	};
 
-	struct Node : public std::variant<Dir, File> {
-		using super_type = std::variant<Dir, File>;
+	struct Node : public Variant<Dir, File> {
+		using superType = Variant<Dir, File>;
 
 		Node() = default;
 
@@ -74,13 +74,14 @@ namespace Arc {
 
 		QVariant data(QModelIndex const &index, int role) const override;
 		Qt::ItemFlags flags(QModelIndex const &index) const override;
-		QVariant headerData(int section, Qt::Orientation orientation, int role)
+		QVariant headerData(int section, Qt::Orientation ori, int role)
 			const override;
 		QModelIndex index(int row,
-	                  	int col,
-	                  	QModelIndex const &parent = QModelIndex())
+		                  int col,
+		                  QModelIndex const &parent = QModelIndex())
+			const override;
+		QModelIndex parent(QModelIndex const &index = QModelIndex())
 			const override;
-		QModelIndex parent(QModelIndex const &index = QModelIndex()) const override;
 		int rowCount(QModelIndex const &index = QModelIndex()) const override;
 		int columnCount(QModelIndex const &index = QModelIndex()) const override;
 
@@ -100,4 +101,12 @@ Q_DECLARE_METATYPE(Arc::Dir)
 Q_DECLARE_METATYPE(Arc::File)
 Q_DECLARE_METATYPE(Arc::Node)
 
+static inline QDebug operator<<(QDebug debug, Arc::Node const &t) {
+	debug << "Arc::Node(" << t.name << ", ";
+	std::visit([&](auto &&arg) {debug << arg;},
+	           static_cast<Variant<Arc::Dir, Arc::File>>(t));
+	debug << ")";
+	return debug;
+}
+
 // EOF
diff --git a/source/quam/pack.cc b/source/quam/pack.cc
index b2cc772..6ccff84 100644
--- a/source/quam/pack.cc
+++ b/source/quam/pack.cc
@@ -59,7 +59,7 @@ static PackEntry readPackEntry(std::istream &st) {
 	return ent;
 }
 
-static void insertFile(Arc::Dir &dir, std::string name, Arc::File file) {
+static void insertFile(Arc::Dir &dir, std::string &name, Arc::File &file) {
 	Option<std::string> next;
 
 	if(auto slash = name.find('/'); slash != std::string::npos) {
@@ -68,18 +68,14 @@ static void insertFile(Arc::Dir &dir, std::string name, Arc::File file) {
 	}
 
 	auto existing = dir.findNode(name);
-
 	if(next) {
-		auto ref =
-			existing != dir.end()
-				? *existing
-				: dir.emplace_back(Arc::Dir{}, std::move(name));
-		insertFile(std::get<Arc::Dir>(ref), *std::move(next), std::move(file));
-	} else {
-		if(existing != dir.end()) {
-			throw FileFormatError("duplicate file");
-		}
+		auto &ref = existing ? *existing
+		                     : dir.emplace_back(Arc::Dir{}, std::move(name));
+		insertFile(std::get<Arc::Dir>(ref), *next, file);
+	} else if(!existing) {
 		dir.emplace_back(std::move(file), std::move(name));
+	} else {
+		throw FileFormatError("duplicate file");
 	}
 }
 
@@ -91,7 +87,7 @@ Arc::Dir readPack(std::istream &st) {
 
 	for(quint32 i = 0; i < hdr.dirNum; i++) {
 		auto ent = readPackEntry(st);
-		insertFile(root, std::move(ent.name), std::move(ent.file));
+		insertFile(root, ent.name, ent.file);
 	}
 
 	return root;
diff --git a/source/quam/project.cc b/source/quam/project.cc
index 0eaa21f..c13805c 100644
--- a/source/quam/project.cc
+++ b/source/quam/project.cc
@@ -19,7 +19,10 @@ Project::Project(Arc::Dir &&arc, QErrorMessage *errors, QMdiArea *parent) :
 	setAttribute(Qt::WA_DeleteOnClose);
 	showMaximized();
 
-	connect(m_model, &Arc::Model::dirChanged, this, &Project::dirChanged);
+	connect(m_model, &Arc::Model::dirChanged,
+	        this,    &Project::dirChanged);
+	connect(tableView, &QAbstractItemView::doubleClicked,
+	        this,      &Project::viewDoubleClicked);
 
 	m_sorter->setSourceModel(m_model);
 	tableView->setModel(m_sorter);
@@ -33,4 +36,12 @@ void Project::dirChanged(Arc::Dir *) {
 	tableView->resizeColumnsToContents();
 }
 
+void Project::viewDoubleClicked(QModelIndex const &index) {
+	auto node = static_cast<Arc::Node *>(index.data(Qt::UserRole)
+	                                          .value<void *>());
+	if(auto dir = std::get_if<Arc::Dir>(node)) {
+		m_model->setDir(dir);
+	}
+}
+
 // EOF
diff --git a/source/quam/project.h b/source/quam/project.h
index 8ffcc52..73a1826 100644
--- a/source/quam/project.h
+++ b/source/quam/project.h
@@ -22,6 +22,7 @@ public:
 
 private slots:
 	void dirChanged(Arc::Dir *dir);
+	void viewDoubleClicked(QModelIndex const &index);
 
 private:
 	Arc::Dir               m_arc;
diff --git a/source/quam/wad2.cc b/source/quam/wad2.cc
index 6ec9d21..996bb2b 100644
--- a/source/quam/wad2.cc
+++ b/source/quam/wad2.cc
@@ -82,11 +82,6 @@ Arc::Dir readWad2(std::istream &st) {
 
 	for(quint32 i = 0; i < hdr.dirNum; i++) {
 		auto ent = readWad2Entry(st);
-		/*
-		if(root.findNode(ent.name) != root.end()) {
-			throw FileFormatError("duplicate file");
-		}
-		*/
 		root.emplace_back(std::move(ent.file), std::move(ent.name), ent.type);
 	}