diff --git a/frontend/src/js/component/wb-collection-content.js b/frontend/src/js/component/wb-collection-content.js
index ea419a0..05c3caa 100644
--- a/frontend/src/js/component/wb-collection-content.js
+++ b/frontend/src/js/component/wb-collection-content.js
@@ -75,9 +75,13 @@ class WBCollectionContent extends Component {
         });
       }
 
-      prom_1 = prom_1.then(e =>  this.setState({
-          'mode': 'browsingReady'
-      }));
+      prom_1 = prom_1.then(() => manifestWorker.postMessage([ 'listDirectory',
+        '.' + this.props.collectionPath, true ]));
+
+      prom_1 = prom_1.then(e => {
+        this.state.mode = 'browsingReady';
+        this.prepareRows(e.data[1]);
+      });
 
       return prom_1;
     });
diff --git a/frontend/src/js/misc/wb-manifest-worker-wrapper.js b/frontend/src/js/misc/wb-manifest-worker-wrapper.js
index c165fd1..891ad55 100644
--- a/frontend/src/js/misc/wb-manifest-worker-wrapper.js
+++ b/frontend/src/js/misc/wb-manifest-worker-wrapper.js
@@ -9,13 +9,16 @@ class WBManifestWorkerWrapper {
   onMessage(e) {
     if (this.queue.length === 0)
       throw Error('Unexpected message from worker');
-    const accept = this.queue.splice(0, 1)[0];
-    accept(e);
+    const [msgType, accept, reject] = this.queue.splice(0, 1)[0];
+    if (e.data[0] === msgType + 'Result')
+      accept(e);
+    else
+      reject(e);
   }
 
   postMessage(m) {
-    const prom = new Promise(accept => {
-      this.queue.push(accept);
+    const prom = new Promise((accept, reject) => {
+      this.queue.push([ m[0], accept, reject ]);
       this.worker.postMessage(m);
     });
     return prom;
diff --git a/frontend/src/js/worker/wb-manifest-worker.js b/frontend/src/js/worker/wb-manifest-worker.js
index 65ba1bd..d9138ce 100644
--- a/frontend/src/js/worker/wb-manifest-worker.js
+++ b/frontend/src/js/worker/wb-manifest-worker.js
@@ -4,23 +4,28 @@ const streams = [];
 
 onmessage = function(e) {
   switch (e.data[0]) {
-  case 'precreatePaths':
-    precreatePaths(e.data[1]);
-    postMessage([ 'precreatePathsResult' ]);
-    break;
-  case 'parseStream':
-    parseStream(e.data[1]);
-    postMessage([ 'parseStreamResult' ]);
-    break;
-  case 'listDirectory': {
-    const lst = listDirectory(rootDir, e.data[1], e.data[2]);
-    postMessage([ 'listDirectoryResult', lst ])
-    break; }
-  case 'getData': {
-    postMessage([ 'getDataResult', rootDir, streams ]);
-  break; }
-  default:
-    throw Error('Unknown verb: ' + e.data[0]);
+    case 'precreatePaths':
+      precreatePaths(e.data[1]);
+      postMessage([ 'precreatePathsResult' ]);
+      break;
+    case 'parseStream':
+      parseStream(e.data[1]);
+      postMessage([ 'parseStreamResult' ]);
+      break;
+    case 'listDirectory': {
+      const lst = listDirectory(rootDir, e.data[1], e.data[2]);
+      postMessage([ 'listDirectoryResult', lst ])
+      break; }
+    case 'getData':
+      postMessage([ 'getDataResult', rootDir, streams ]);
+      break;
+    case 'getFile':
+      postMessage([ 'getFileResult', getFile(rootDir, streams, e.data[1]) ]);
+      break;
+    default: {
+      const err = Error('Unknown verb: ' + e.data[0]);
+      postMessage([ 'error', err.message ]);
+      throw err; }
   }
 }
 
@@ -141,3 +146,41 @@ function listDirectory(rootDir, path, lenient=false) {
   res = res.concat(files.map(k => [ 'f', k, dir[k][1] ]));
   return res;
 }
+
+function getFile(rootDir, streams, path) {
+  if (typeof(path) === 'string')
+    path = path.split('/');
+
+  if (path.length < 2)
+    throw Error('Invalid file path');
+
+  const name = path[path.length - 1];
+
+  const dir = findDir(rootDir, path.slice(0, path.length - 1));
+
+  if (!(name in dir))
+    throw Error('File not found');
+
+  if (!(dir[name] instanceof Array))
+    throw Error('Path points to a directory not a file');
+
+  let file = dir[name];
+  file = [ file[0].map(seg => {
+    const stm = streams[seg[0]];
+    const used = stm.map(loc => !( loc[2] <= seg[1] || loc[1] >= seg[1] + seg[2] ) );
+    const start = used.indexOf(true);
+    const end = used.lastIndexOf(true) + 1;
+    if (start === -1)
+      return [];
+    const res = [];
+    for (let i = start; i < end; i++) {
+      const loc = stm[i];
+      res.push([ loc[0], Math.max(0, seg[1] - loc[1]),
+        Math.min(loc[2] - loc[1], seg[1] + seg[2] - loc[1]) ]);
+    }
+    return res;
+  }), file[1] ];
+  file[0] = file[0].reduce((a, b) => a.concat(b));
+
+  return file;
+}