diff --git a/backend/app.py b/backend/app.py
index d828ff0..adb4202 100644
--- a/backend/app.py
+++ b/backend/app.py
@@ -77,6 +77,73 @@ def get_podcast(podcast_id: str):
     }
 
 
+@app.get("/api/podcasts/{podcast_id}/network")
+def get_podcast_network(podcast_id: str, top_per_episode: int = 2, min_score: float = 0.65):
+    """Mindmap-Querverbindungen (#19): Top-N Episode-Episode-Links per Aehnlichkeit
+    sowie Episode-Pair-Aggregate aus argument_links."""
+    db = get_db()
+
+    # Episode-Episode similarity: pro source-Episode die staerksten N Targets
+    sim_rows = db.execute(
+        "SELECT source_episode, target_podcast, target_episode, MAX(score) AS top_score, COUNT(*) AS n_links "
+        "FROM semantic_links "
+        "WHERE podcast_id = ? AND source_episode != target_episode "
+        "GROUP BY source_episode, target_podcast, target_episode "
+        "HAVING top_score >= ? "
+        "ORDER BY source_episode, top_score DESC",
+        (podcast_id, min_score),
+    ).fetchall()
+
+    # In Python auf top_per_episode pro Source einschraenken
+    per_src = {}
+    sim_links = []
+    for r in sim_rows:
+        src = r["source_episode"]
+        if per_src.get(src, 0) >= top_per_episode:
+            continue
+        sim_links.append({
+            "source_episode": src,
+            "target_podcast": r["target_podcast"],
+            "target_episode": r["target_episode"],
+            "score": r["top_score"],
+            "n_paragraph_links": r["n_links"],
+        })
+        per_src[src] = per_src.get(src, 0) + 1
+
+    # Argument-Links: aggregiert pro Episode-Pair und Relation
+    arg_links = []
+    if _table_exists(db, "argument_links"):
+        arg_rows = db.execute(
+            "SELECT source_episode, target_podcast, target_episode, relation, COUNT(*) AS n "
+            "FROM argument_links "
+            "WHERE source_podcast = ? AND relation NOT IN ('error', 'kein_bezug') "
+            "GROUP BY source_episode, target_podcast, target_episode, relation "
+            "ORDER BY n DESC",
+            (podcast_id,),
+        ).fetchall()
+        # Aggregate per Episode-Pair
+        pair_map = {}
+        for r in arg_rows:
+            key = (r["source_episode"], r["target_podcast"], r["target_episode"])
+            pair_map.setdefault(key, {})[r["relation"]] = r["n"]
+        for (src, tp, te), counts in pair_map.items():
+            arg_links.append({
+                "source_episode": src,
+                "target_podcast": tp,
+                "target_episode": te,
+                "counts": counts,
+            })
+
+    db.close()
+    return {
+        "podcast_id": podcast_id,
+        "top_per_episode": top_per_episode,
+        "min_score": min_score,
+        "similarity_links": sim_links,
+        "argument_links": arg_links,
+    }
+
+
 @app.get("/api/podcasts/{podcast_id}/transcript/{episode_id}")
 def get_transcript(podcast_id: str, episode_id: str):
     db = get_db()
diff --git a/webapp/index.html b/webapp/index.html
index 62d18bb..b592885 100644
--- a/webapp/index.html
+++ b/webapp/index.html
@@ -407,7 +407,9 @@
 // ============================================================
 
 let DATA = null;
+let NETWORK = null; // Mindmap-Querverbindungen (#19): similarity + argument links
 let TRANSCRIPTS = null; // loaded on demand
+const LINK_VISIBILITY = { 'quote-theme': false, 'episode-similar': true, 'arg-belegt': true, 'arg-widerspricht': true, 'arg-erweitert': true, 'arg-relativiert': false };
 let simulation = null;
 
 // Audio state — completely independent from panel state
@@ -1939,8 +1941,12 @@ async function loadApp() {
 
 async function selectPodcast(podcastId, fromUrl = false) {
   try {
-    const resp = await fetch(`${API_BASE}/api/podcasts/${podcastId}`);
+    const [resp, netResp] = await Promise.all([
+      fetch(`${API_BASE}/api/podcasts/${podcastId}`),
+      fetch(`${API_BASE}/api/podcasts/${podcastId}/network?top_per_episode=2`).catch(() => null),
+    ]);
     DATA = await resp.json();
+    NETWORK = netResp && netResp.ok ? await netResp.json() : null;
     CURRENT_PODCAST = podcastId;
     if (!fromUrl && window.history && window.location.pathname !== `/${podcastId}`) {
       window.history.pushState({ podcast: podcastId }, '', `/${podcastId}`);
@@ -2286,6 +2292,37 @@ function buildGraph() {
         isTopQuote: q.isTopQuote, verbatim: q.verbatim,
         r: (q.isTopQuote ? 6 : 4) * sc, color: ep ? ep.color : '#666', staffel: ep ? ep.staffel : 0 });
       links.push({ source: q.episode, target: q.id, type: 'episode-quote' });
+      // #19: Quote ↔ Theme-Tags (zusaetzlich zur Episode-Verbindung)
+      if (hasThemes && Array.isArray(q.themes)) {
+        q.themes.forEach(tid => {
+          if (DATA.themes.find(t => t.id === tid)) {
+            links.push({ source: q.id, target: tid, type: 'quote-theme' });
+          }
+        });
+      }
+    });
+  }
+
+  // #19: Episode ↔ Episode (semantische Aehnlichkeit) und Argument-Pair-Links
+  if (NETWORK) {
+    (NETWORK.similarity_links || []).forEach(s => {
+      // Nur intra-podcast und nur wenn beide Endpunkte als Episoden-Knoten existieren
+      if (s.target_podcast === CURRENT_PODCAST && episodeMap[s.source_episode] && episodeMap[s.target_episode]) {
+        links.push({ source: s.source_episode, target: s.target_episode, type: 'episode-similar', score: s.score });
+      }
+    });
+    (NETWORK.argument_links || []).forEach(a => {
+      if (a.target_podcast !== CURRENT_PODCAST) return;
+      if (!episodeMap[a.source_episode] || !episodeMap[a.target_episode]) return;
+      // Pro Pair: dominante Relation als eigene Linie (top-count entscheidet)
+      const counts = a.counts || {};
+      const order = ['widerspricht', 'belegt', 'erweitert', 'relativiert'];
+      let dom = null;
+      for (const r of order) {
+        if (counts[r]) { dom = r; break; }
+      }
+      if (!dom) return;
+      links.push({ source: a.source_episode, target: a.target_episode, type: `arg-${dom}`, n: counts[dom] });
     });
   }
 
@@ -2293,8 +2330,18 @@ function buildGraph() {
     .force('link', d3.forceLink(links).id(d => d.id).distance(d => {
       if (d.type === 'center-theme') return 160 * sc;
       if (d.type === 'theme-episode') return 100 * sc;
+      if (d.type === 'episode-similar') return 90 * sc;
+      if (d.type && d.type.startsWith('arg-')) return 110 * sc;
+      if (d.type === 'quote-theme') return 70 * sc;
       return 50 * sc;
-    }).strength(d => d.type === 'center-theme' ? 0.8 : d.type === 'theme-episode' ? 0.3 : 0.2))
+    }).strength(d => {
+      if (d.type === 'center-theme') return 0.8;
+      if (d.type === 'theme-episode') return 0.3;
+      if (d.type === 'episode-similar') return 0.05;
+      if (d.type && d.type.startsWith('arg-')) return 0.08;
+      if (d.type === 'quote-theme') return 0.05;
+      return 0.2;
+    }))
     .force('charge', d3.forceManyBody().strength(d => {
       if (d.type === 'center') return -800 * sc;
       if (d.type === 'theme') return -400 * sc;
@@ -2310,11 +2357,28 @@ function buildGraph() {
 
   const g = svg.append('g');
 
+  // #19: Link-Style je Typ
+  const LINK_STYLE = {
+    'episode-similar':   { stroke: '#7dd3fc', dash: '4,4',  width: 1.0, opacity: 0.55 },
+    'arg-belegt':        { stroke: '#86efac', dash: null,    width: 1.6, opacity: 0.85 },
+    'arg-widerspricht':  { stroke: '#f87171', dash: null,    width: 1.8, opacity: 0.9 },
+    'arg-erweitert':     { stroke: '#60a5fa', dash: null,    width: 1.4, opacity: 0.75 },
+    'arg-relativiert':   { stroke: '#9ca3af', dash: '2,3',  width: 1.0, opacity: 0.6 },
+    'quote-theme':       { stroke: '#a3a3a3', dash: '1,3',  width: 0.6, opacity: 0.35 },
+  };
+
   const linkEls = g.append('g').selectAll('line').data(links).join('line')
     .attr('class', d => `link link-${d.type}`)
     .attr('stroke', d => {
+      if (LINK_STYLE[d.type]) return LINK_STYLE[d.type].stroke;
       const src = nodes.find(n => n.id === (typeof d.source === 'object' ? d.source.id : d.source));
       return src ? src.color : '#374151';
+    })
+    .attr('stroke-dasharray', d => LINK_STYLE[d.type]?.dash || null)
+    .attr('stroke-width', d => LINK_STYLE[d.type]?.width ?? 1)
+    .attr('opacity', d => {
+      if (LINK_STYLE[d.type] && LINK_VISIBILITY[d.type] === false) return 0;
+      return LINK_STYLE[d.type]?.opacity ?? 1;
     });
 
   const nodeG = g.append('g');
@@ -2353,6 +2417,50 @@ function buildGraph() {
 
   window._nodes = nodes; window._quoteNodes = quoteNodes;
   window._epNodes = epNodes; window._themeNodes = themeNodes; window._linkEls = linkEls;
+  window._linkStyle = LINK_STYLE;
+
+  // #19: Toggle-Panel rechts oben in der Mindmap
+  renderLinkToggles();
+}
+
+function renderLinkToggles() {
+  const mm = document.getElementById('mindmap');
+  let panel = document.getElementById('link-toggles');
+  if (panel) panel.remove();
+  panel = document.createElement('div');
+  panel.id = 'link-toggles';
+  panel.style.cssText = 'position:absolute;top:8px;right:8px;background:rgba(20,24,32,0.85);border:1px solid var(--border);border-radius:6px;padding:6px 8px;font-size:11px;display:flex;flex-direction:column;gap:3px;z-index:5;backdrop-filter:blur(4px)';
+  const labels = {
+    'episode-similar': 'aehnliche Episoden',
+    'arg-belegt': 'belegt',
+    'arg-widerspricht': 'widerspricht',
+    'arg-erweitert': 'erweitert',
+    'arg-relativiert': 'relativiert',
+    'quote-theme': 'Quote-Theme',
+  };
+  panel.innerHTML = `<div style="font-weight:600;color:var(--text-muted);margin-bottom:2px">Verbindungen</div>`;
+  Object.keys(labels).forEach(t => {
+    const style = window._linkStyle?.[t];
+    const checked = LINK_VISIBILITY[t] !== false;
+    panel.innerHTML += `<label style="display:flex;align-items:center;gap:6px;cursor:pointer">
+      <input type="checkbox" data-link="${t}" ${checked ? 'checked' : ''} style="margin:0">
+      <span style="display:inline-block;width:18px;height:2px;background:${style?.stroke || '#888'};${style?.dash ? 'background:repeating-linear-gradient(90deg,' + style.stroke + ' 0,' + style.stroke + ' 2px,transparent 2px,transparent 5px)' : ''}"></span>
+      <span>${labels[t]}</span>
+    </label>`;
+  });
+  mm.style.position = 'relative';
+  mm.appendChild(panel);
+  panel.querySelectorAll('input').forEach(cb => {
+    cb.addEventListener('change', () => {
+      LINK_VISIBILITY[cb.dataset.link] = cb.checked;
+      if (window._linkEls) {
+        window._linkEls.attr('opacity', d => {
+          if (window._linkStyle[d.type] && LINK_VISIBILITY[d.type] === false) return 0;
+          return window._linkStyle[d.type]?.opacity ?? 1;
+        });
+      }
+    });
+  });
 }
 
 function updateVisibility() {