diff --git a/www/_templates/front_doc_listing.php b/www/_templates/front_doc_listing.php
index c6789a2..85e539a 100644
--- a/www/_templates/front_doc_listing.php
+++ b/www/_templates/front_doc_listing.php
@@ -1,7 +1,8 @@
-<?php if (isset($tag)): ?>
+<?php /** @noinspection PhpUndefinedVariableInspection */
+if (isset($tag)): ?>
     <div class="text tag-text">
         <h1><?= $tag["Name"] ?></h1>
-        <p class="tag-desc"><?= $tag["Description"] ?></p>
+        <p class="tag-desc"><?= $tag["HTMLDescription"] ?></p>
     </div>
 <?php endif; ?>
 
diff --git a/www/_templates/front_doc_overview.php b/www/_templates/front_doc_overview.php
index 9fa36c0..7325e72 100644
--- a/www/_templates/front_doc_overview.php
+++ b/www/_templates/front_doc_overview.php
@@ -19,10 +19,10 @@
         </h3>
     <?php endif; ?>
 
-    <?php if (!empty($doc["Description"])): ?>
+    <?php if ($doc["HTMLDescription"]): ?>
         <p class="doc-description"><span
                     class="doc-description-intro"><?= empty($doc["URL"]) ? "Content" : "Description" ?>
-                : </span><?= $doc["Description"] ?></p>
+                : </span><?= $doc["HTMLDescription"] ?></p>
     <?php endif; ?>
 
     <div class="doc-link"><span class="doc-link-intro">Get print label: </span>
diff --git a/www/_templates/label_template.php b/www/_templates/label_template.php
index fcedf78..df730fd 100644
--- a/www/_templates/label_template.php
+++ b/www/_templates/label_template.php
@@ -107,7 +107,7 @@
                     <div class="label-otherinfo-date">(Published: <?= $doc["Published"] ?>)</div>
                 <?php endif; ?>
             </h3>
-            <p class="label-description"><?= $doc["Description"] ?></p>
+            <p class="label-description"><?= $doc["HTMLDescription"] ?></p>
         </div>
     </div>
     <div class="label-footer">
diff --git a/www/_util/PileDB.php b/www/_util/PileDB.php
index f8a324c..560edea 100644
--- a/www/_util/PileDB.php
+++ b/www/_util/PileDB.php
@@ -2,11 +2,13 @@
 
 class PileDB
 {
-    private $db;
+    protected $db;
+    private $pd;
 
     function __construct($dbpath = "pile.db")
     {
         $this->db = new SQLite3($dbpath);
+        $this->pd = new Parsedown();
     }
 
     function prepare($statement)
@@ -59,11 +61,20 @@ class PileDB
         return $tags;
     }
 
+    /**
+     * Fetch pile document as an associative array.
+     *
+     * @throws DocumentNotFoundException when document isn't found.
+     */
     public function fetchDoc($id)
     {
         $stmt_doc = $this->db->prepare("SELECT * FROM Documents WHERE ID = :id");
         $stmt_doc->bindValue(":id", $id, SQLITE3_INTEGER);
         $doc = $stmt_doc->execute()->fetchArray(SQLITE3_ASSOC);
+        if ($doc == false) {
+            throw new DocumentNotFoundException();
+        }
+        $doc["HTMLDescription"] = $this->pd->text($doc["Description"]);
 
         $stmt_tags = $this->db->prepare("SELECT t.ID, t.Name FROM Tags t
                                                 JOIN DocumentsToTags dt ON t.ID = dt.Tag
@@ -194,7 +205,9 @@ class PileDB
     {
         $stmt = $this->db->prepare("SELECT * FROM Tags WHERE ID == :tag");
         $stmt->bindValue(":tag", $tag, SQLITE3_INTEGER);
-        return $stmt->execute()->fetchArray(SQLITE3_ASSOC);
+        $tag = $stmt->execute()->fetchArray(SQLITE3_ASSOC);
+        $tag["HTMLDescription"] = $this->pd->text($tag["Description"]);
+        return $tag;
     }
 
     public function updateTag($id, $name, $description)
@@ -244,4 +257,9 @@ class PileDB
     }
 }
 
+class DocumentNotFoundException extends Exception
+{
+    // noop
+}
+
 ?>
diff --git a/www/index.php b/www/index.php
index 87eb694..8457aa4 100644
--- a/www/index.php
+++ b/www/index.php
@@ -4,12 +4,19 @@ require '_util/PileDB.php';
 require '_vendor/erusev/parsedown/Parsedown.php';
 
 $db = new PileDB();
-$pd = new Parsedown();
 session_start();
+$page = new Template();
 
 if (isset($_GET["item"])) {
-    $doc = $db->fetchDoc($_GET["item"]);
-    $doc["Description"] = $pd->text($doc["Description"]);
+    try {
+        $doc = $db->fetchDoc($_GET["item"]);
+    } catch (DocumentNotFoundException $e) {
+        http_response_code(404);
+        $page->text = "Document not found.";
+        $page->redirect = "/";
+        echo $page->render("full_text.php");
+        die(0);
+    }
 
     $doc_template = new Template();
     $doc_template->doc = $doc;
@@ -27,7 +34,6 @@ if (isset($_GET["item"])) {
             $tag = $db->findTag($_GET["tag"]);
         }
         $docs = $db->listDocs($tag["ID"]);
-        $tag["Description"] = $pd->text($tag["Description"]);
         $selected_tag = $tag;
         $doc_list_template->tag = $tag;
     }
@@ -39,7 +45,6 @@ if (isset($_GET["item"])) {
     $content = $intro_template->render('front_intro.php');
 }
 
-$page = new Template();
 $page->doc_count = $db->getDocCount();
 $page->none_count = $db->getUntaggedDocCount();
 $page->tags = $db->getTags();
diff --git a/www/label.php b/www/label.php
index c083dc0..68cc8e8 100644
--- a/www/label.php
+++ b/www/label.php
@@ -6,13 +6,16 @@ require '_templates/Template.php';
 require '_util/PileDB.php';
 
 
-use Mpdf\Mpdf;
-
 $db = new PileDB();
-$doc = $db->fetchDoc($_GET["id"]);
-
-$pd = new Parsedown();
-$doc["Description"] = $pd->text($doc["Description"]);
+try {
+    $doc = $db->fetchDoc($_GET["id"]);
+} catch (DocumentNotFoundException $e) {
+    http_response_code(404);
+    $page->text = "Document not found.";
+    $page->redirect = "/";
+    echo $page->render("full_text.php");
+    die(0);
+}
 
 $front = new Template();
 $front->doc = $doc;
@@ -38,7 +41,7 @@ try {
     $mpdf->showImageErrors = true;
     $mpdf->WriteHTML($front->render("_templates/label_template.php"));
     $mpdf->Output();
-} catch (\Mpdf\MpdfException $exception) {
+} catch (Exception $exception) {
     http_response_code(500); ?>
     <h1>Something went wrong generating the label.</h1>
     <pre><?= $exception->getMessage() ?></pre>