diff --git a/src/handlers.go b/src/handlers.go
index f68a244..ee9d1dc 100644
--- a/src/handlers.go
+++ b/src/handlers.go
@@ -10,7 +10,9 @@ import (
 	"log"
 	"net/http"
 	"os"
+	"path"
 	"path/filepath"
+	"regexp"
 	"strconv"
 	"strings"
 )
@@ -265,15 +267,16 @@ func (ctx *Instance) dehydrateHandler(w http.ResponseWriter, req *http.Request)
 
 	zipWriter := zip.NewWriter( buf )
 
+	// Package up important JSON endpoints
 	writeZipContents(zipWriter, fmt.Sprintf("%s/%s", zipBaseDir, "puzzles.json"), ctx.jPuzzleList)
 	writeZipContents(zipWriter, fmt.Sprintf("%s/%s", zipBaseDir, "points.json"), ctx.jPointsLog)
 
+	// Package up files for currently-unlocked puzzles in categories
 	for category_name, category := range ctx.categories {
 		for _, file := range category.zf.File {
 			parts := strings.Split(file.Name, "/")
 
 			if (parts[0] == "content") {
-				fmt.Printf("Inspecting %s/%s\n", category_name, file.Name)
 				local_buf := new(bytes.Buffer)
 				fh, _ := file.Open()
 				defer fh.Close()
@@ -283,17 +286,21 @@ func (ctx *Instance) dehydrateHandler(w http.ResponseWriter, req *http.Request)
 		}
 	}
 
+	// Pack up the theme files
+	theme_root_re := regexp.MustCompile(fmt.Sprintf("^%s", ctx.ThemeDir))
 	filepath.Walk(ctx.ThemeDir, func (path string, info os.FileInfo, err error) error {
 		if err != nil {
 			return err
 		}
-		if ! info.IsDir() {
-			fmt.Printf("Walking %s\n", path)
+
+		if ! info.IsDir() { // Only package up files
 			local_buf := new(bytes.Buffer)
 			fh, _ := os.Open(path)
 			defer fh.Close()
 			local_buf.ReadFrom(fh)
-			writeZipContents(zipWriter, fmt.Sprintf("%s/%s", zipBaseDir, path), local_buf.Bytes())
+			localized_path := theme_root_re.ReplaceAllLiteralString( path, "")
+			fmt.Printf("Localized path is %s\n", localized_path)
+			writeZipContents(zipWriter, fmt.Sprintf("%s/%s", zipBaseDir, localized_path), local_buf.Bytes())
 		}
 		return nil
 	})
@@ -305,7 +312,44 @@ func (ctx *Instance) dehydrateHandler(w http.ResponseWriter, req *http.Request)
 	w.Write(buf.Bytes())
 }
 
+func (ctx *Instance) manifestHandler(w http.ResponseWriter, req *http.Request) {
+	manifest := make([]string, 0)
+	manifest = append(manifest, "puzzles.json")
+	manifest = append(manifest, "points.json")
+
+	// Pack up the theme files
+	theme_root_re := regexp.MustCompile(fmt.Sprintf("^%s/", ctx.ThemeDir))
+	filepath.Walk(ctx.ThemeDir, func (path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if ! info.IsDir() { // Only package up files
+			localized_path := theme_root_re.ReplaceAllLiteralString( path, "")
+			manifest = append(manifest, localized_path)
+		}
+		return nil
+	})
+
+	// Package up files for currently-unlocked puzzles in categories
+	for category_name, category := range ctx.categories {
+		for _, file := range category.zf.File {
+			parts := strings.Split(file.Name, "/")
+
+			if (parts[0] == "content") {
+				manifest = append(manifest, path.Join("content", category_name, path.Join(parts[1:]...)))
+			}
+		}
+	}
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	manifest_json, _ := json.Marshal(manifest)
+	w.Write(manifest_json)
+}
+
 func writeZipContents(z *zip.Writer, path string, contents []byte) error {
+	path = filepath.Clean(path)
+	fmt.Printf("Writing contents to %s\n", path)
 	f, err := z.Create(path)
 	if err != nil {
 		return err
@@ -357,5 +401,6 @@ func (ctx *Instance) BindHandlers() {
 	ctx.mux.HandleFunc(ctx.Base+"/content/", ctx.contentHandler)
 	ctx.mux.HandleFunc(ctx.Base+"/puzzles.json", ctx.puzzlesHandler)
 	ctx.mux.HandleFunc(ctx.Base+"/points.json", ctx.pointsHandler)
+	ctx.mux.HandleFunc(ctx.Base+"/state_manifest.json", ctx.manifestHandler)
 	ctx.mux.HandleFunc(ctx.Base+"/dehydrate", ctx.dehydrateHandler)
 }
diff --git a/theme/index.html b/theme/index.html
index 89bdf48..811878e 100644
--- a/theme/index.html
+++ b/theme/index.html
@@ -5,7 +5,9 @@
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width">
     <link rel="stylesheet" href="basic.css">
+    <script src="moth-pwa.js" type="text/javascript"></script>
     <script src="moth.js"></script>
+    <link rel="manifest" href="manifest.json">
   </head>
   <body>
     <h1 id="title">MOTH</h1>
@@ -20,7 +22,7 @@
 
       <div id="puzzles"></div>
 
-		</section>
+    </section>
     <nav>
       <ul>
         <li><a href="scoreboard.html">Scoreboard</a></li>
diff --git a/theme/manifest.json b/theme/manifest.json
new file mode 100644
index 0000000..4a50304
--- /dev/null
+++ b/theme/manifest.json
@@ -0,0 +1,9 @@
+{
+  "name": "Monarch of the Hill",
+  "short_name": "MOTH",
+  "start_url": ".",
+  "display": "standalone",
+  "background_color": "#fff",
+  "theme_color": "#ECB",
+  "description": "The MOTH CTF engine"
+}
diff --git a/theme/moth-pwa.js b/theme/moth-pwa.js
new file mode 100644
index 0000000..7858c80
--- /dev/null
+++ b/theme/moth-pwa.js
@@ -0,0 +1,18 @@
+function pwa_init() {
+  console.log("Starting service worker");
+  if ('serviceWorker' in navigator) {
+    navigator.serviceWorker.register("./sw.js").then(function(reg) {
+      console.log("Successfully registered service worker", reg);
+    }).catch(function(err) {
+      console.warn("Error while registering service worker", err);
+    });
+  } else {
+    console.log("Service workers not supported. Some offline functionality may not work");
+  }
+}
+
+if (document.readyState === "loading") {
+  document.addEventListener("DOMContentLoaded", pwa_init);
+} else {
+  pwa_init();
+}
diff --git a/theme/moth.js b/theme/moth.js
index f6f99ec..f7d7c67 100644
--- a/theme/moth.js
+++ b/theme/moth.js
@@ -78,12 +78,7 @@ function renderPuzzles(obj) {
 }
 
 function heartbeat(teamId) {
-  let fd = new FormData()
-  fd.append("id", teamId)
-  fetch("puzzles.json", {
-    method: "POST",
-    body: fd,
-  })
+  fetch("puzzles.json?id=" + teamId)
   .then(resp => {
     if (resp.ok) {
       resp.json()
@@ -110,6 +105,68 @@ function showPuzzles(teamId) {
   document.getElementById("puzzles").appendChild(spinner)
   heartbeat(teamId)
   setInterval(e => { heartbeat(teamId) }, 40000)
+
+  let cacher = document.createElement("li");
+  let cache_button = document.createElement("a");
+  cache_button.innerText = "Cache";
+  cache_button.title = "Cache an offine copy of current content";
+  cache_button.href = "#";
+  cache_button.addEventListener("click", async function() {
+    toast("Caching all currently-open content");
+    await fetchAll(teamId);
+    toast("Done caching content");
+  });
+  cacher.appendChild(cache_button);
+  document.getElementsByTagName("nav")[0].getElementsByTagName("ul")[0].appendChild(cacher);
+}
+
+async function fetchAll(teamId) {
+  let headers = new Headers();
+  headers.append("pragma", "no-cache");
+  headers.append("cache-control", "no-cache");
+  requests = [];
+
+  requests.push( fetch("state_manifest.json?id=" + teamId, {headers: headers})
+   .then( resp => {
+    if (resp.ok) {
+      resp.json()
+       .then( contents => {
+        console.log("Processing manifest");
+        for (let resource of contents) {
+          if (resource == "puzzles.json") {
+            continue;
+          }
+          fetch(resource, {headers: headers})
+           .then( e => {
+            console.log("Fetched " + resource);
+          })
+        }
+      })
+   }
+  }));
+
+  let resp = await fetch("puzzles.json?id=" + teamId, {headers: headers});
+	
+  if (resp.ok) {
+    let categories = await resp.json();
+    let cat_names = Object.keys(categories)
+    cat_names.sort()
+    for (let cat_name of cat_names) {
+      if (cat_name.startsWith("__")) {
+        // Skip metadata
+        continue
+      }
+      let puzzles = categories[cat_name];
+      for (let puzzle of puzzles) {
+        let url = "puzzle.html?cat=" + cat_name + "&points=" + puzzle[0] + "&pid=" + puzzle[1];
+        requests.push( fetch(url, {headers: headers})
+         .then( e => {
+          console.log("Fetched " + url);
+        }));
+      }
+    }
+  }
+  return Promise.all(requests);
 }
 
 function login(e) {
@@ -156,7 +213,7 @@ function init() {
   if (id) {
     showPuzzles(id)
   }
-  
+
   document.getElementById("login").addEventListener("submit", login)
 }
 
@@ -165,3 +222,4 @@ if (document.readyState === "loading") {
 } else {
   init();
 }
+
diff --git a/theme/puzzle.html b/theme/puzzle.html
index 2a8dcba..a276f9c 100644
--- a/theme/puzzle.html
+++ b/theme/puzzle.html
@@ -5,6 +5,7 @@
     <link rel="stylesheet" href="basic.css">
     <meta name="viewport" content="width=device-width">
     <meta charset="utf-8">
+    <script src="moth-pwa.js" type="text/javascript"></script>
     <script src="puzzle.js"></script>
     <script>
     
diff --git a/theme/scoreboard.html b/theme/scoreboard.html
index fccae02..5f0742a 100644
--- a/theme/scoreboard.html
+++ b/theme/scoreboard.html
@@ -4,6 +4,7 @@
     <title>Scoreboard</title>
     <link rel="stylesheet" href="basic.css">
     <meta name="viewport" content="width=device-width">
+    <script src="moth-pwa.js" type="text/javascript"></script>
     <script>
 function update(state) {
   let element = document.getElementById("scoreboard");
@@ -111,8 +112,8 @@ function once() {
 }
 
 function init() {
-  let base = window.location.href.replace("scoreboard.html", "")
-  document.querySelector("#location").textContent = base
+  let base = window.location.href.replace("scoreboard.html", "");
+  document.querySelector("#location").textContent = base;
 
   setInterval(once, 60000);
   once();
diff --git a/theme/sw.js b/theme/sw.js
new file mode 100644
index 0000000..fcaf9c3
--- /dev/null
+++ b/theme/sw.js
@@ -0,0 +1,49 @@
+var cacheName =  "moth:v1"
+var content = [
+  "index.html",
+  "basic.css",
+  "puzzle.js",
+  "puzzle.html",
+  "scoreboard.html",
+  "moth.js",
+  "sw.js",
+  "points.json",
+];
+
+self.addEventListener("install", function(e) {
+  e.waitUntil(
+    caches.open(cacheName).then(function(cache) {
+      return cache.addAll(content).then(
+        function() {
+          self.skipWaiting();
+        });
+    })
+  );
+});
+
+/* Attempt to fetch live resources, first, then fall back to cache */
+self.addEventListener('fetch', function(event) {
+  let cache_used = false;
+
+  event.respondWith(
+    fetch(event.request)
+     .catch(function(evt) {
+      console.log("Falling back to cache for " + event.request.url);
+      cache_used = true;
+      return caches.match(event.request, {ignoreSearch: true});
+    }).then(function(res) {
+      if (res && res.ok) {
+        let res_clone = res.clone();
+	if (! cache_used ) {
+          caches.open(cacheName).then(function(cache) {
+            cache.put(event.request, res_clone);
+	    console.log("Storing " + event.request.url + " in cache");
+          });
+	} 
+        return res;
+      } else {
+        console.log("Failed to retrieve resource");
+      }
+    })
+  );
+});