diff --git a/src/tangara/audio/playlist.cpp b/src/tangara/audio/playlist.cpp
index 1436e2d2..f57f078d 100644
--- a/src/tangara/audio/playlist.cpp
+++ b/src/tangara/audio/playlist.cpp
@@ -4,9 +4,12 @@
  * SPDX-License-Identifier: GPL-3.0-only
  */
 #include "playlist.hpp"
+#include <stdint.h>
 
 #include <string>
 
+#include "cppbor.h"
+#include "cppbor_parse.h"
 #include "esp_log.h"
 #include "ff.h"
 
@@ -29,6 +32,7 @@ Playlist::Playlist(const std::string& playlistFilepath)
 
 auto Playlist::open() -> bool {
   std::unique_lock<std::mutex> lock(mutex_);
+
   if (file_open_) {
     return true;
   }
@@ -42,10 +46,12 @@ auto Playlist::open() -> bool {
   file_open_ = true;
   file_error_ = false;
 
-  // Count the playlist size and build our offset cache.
-  countItems();
-  // Advance to the first item.
-  skipToWithoutCache(0);
+  if (!deserialiseCache()) {
+    // Count the playlist size and build our offset cache.
+    countItems();
+    // Advance to the first item.
+    skipToWithoutCache(0);
+  }
 
   return !file_error_;
 }
@@ -100,6 +106,106 @@ auto Playlist::skipTo(size_t position) -> void {
   skipToLocked(position);
 }
 
+// Serialise the cache to a file to avoid having to rescan
+// the entire queue when resuming
+auto Playlist::serialiseCache() -> bool {
+  std::unique_lock<std::mutex> lock(mutex_);
+  if (!file_open_) {
+    return false;
+  }
+
+  FIL file;
+
+  // Open the cache file
+  std::string cache_file = filepath_ + ".cache";
+  FRESULT res =
+      f_open(&file, cache_file.c_str(), FA_READ | FA_WRITE | FA_CREATE_ALWAYS);
+  if (res != FR_OK) {
+    ESP_LOGE(kTag, "failed to open cache file! res: %i", res);
+    return false;
+  }
+
+  cppbor::Array data;
+  // First item = file size of queue file (for checking this file matches)
+  data.add(f_size(&file_));
+  // Next item = number of tracks in this queue
+  data.add(total_size_);
+
+  // Next, write out every cached offset
+  for (uint64_t offset : offset_cache_) {
+    data.add(offset);
+  }
+
+  auto encoded = data.encode();
+
+  UINT bytes_written = 0;
+  f_write(&file, encoded.data(), encoded.size(), &bytes_written);
+  if (bytes_written != encoded.size()) {
+    return false;
+  }
+
+  f_close(&file);
+  return true;
+}
+
+auto Playlist::deserialiseCache() -> bool {
+  if (!file_open_) {
+    return false;
+  }
+
+  FIL file;
+
+  // Open the cache file
+  std::string cache_file = filepath_ + ".cache";
+  FRESULT res =
+      f_open(&file, cache_file.c_str(), FA_READ | FA_WRITE | FA_OPEN_ALWAYS);
+  if (res != FR_OK) {
+    ESP_LOGE(kTag, "failed to open cache file! res: %i", res);
+    return false;
+  }
+
+  std::vector<uint8_t> encoded;
+  encoded.resize(f_size(&file));
+
+  UINT bytes_read;
+  f_read(&file, encoded.data(), encoded.size(), &bytes_read);
+  if (bytes_read != encoded.size()) {
+    return false;
+  }
+
+  auto [data, unused, err] = cppbor::parse(encoded);
+  if (!data || data->type() != cppbor::ARRAY) {
+    return false;
+  }
+  auto entries = data->asArray();
+
+  // Double check the expected file size matches.
+  if (entries->get(0)->asUint()->unsignedValue() != f_size(&file_)) {
+    return false;
+  }
+
+  total_size_ = entries->get(1)->asUint()->unsignedValue();
+
+  // In case we have existing entries
+  offset_cache_.clear();
+
+  // Read in the cache
+  for (size_t i = 2; i < entries->size(); i++) {
+    offset_cache_.push_back(entries->get(i)->asUint()->unsignedValue());
+  }
+
+  f_close(&file);
+  return true;
+}
+
+auto Playlist::close() -> void {
+  if (file_open_) {
+    f_close(&file_);
+    file_open_ = false;
+    file_error_ = false;
+  }
+}
+
 auto Playlist::skipToLocked(size_t position) -> void {
   if (!file_open_ || file_error_) {
     return;
@@ -210,9 +316,46 @@ auto Playlist::nextItem(std::span<TCHAR> buf)
 MutablePlaylist::MutablePlaylist(const std::string& playlistFilepath)
     : Playlist(playlistFilepath) {}
 
+auto MutablePlaylist::open() -> bool {
+  std::unique_lock<std::mutex> lock(mutex_);
+
+  if (file_open_) {
+    return true;
+  }
+  
+  FRESULT res =
+      f_open(&file_, filepath_.c_str(), FA_READ | FA_WRITE | FA_OPEN_ALWAYS);
+  if (res != FR_OK) {
+    ESP_LOGE(kTag, "failed to open file! res: %i", res);
+    return false;
+  }
+  file_open_ = true;
+  file_error_ = false;
+
+  auto queue_filesize = f_size(&file_);
+
+  if (!deserialiseCache()) {
+    // If there's no cache (or deserialising failed) and the queue is
+    // sufficiently large, abort and clear the queue
+    if (queue_filesize > 50000) {
+      clearLocked();
+    } else {
+      // Otherwise, read in the existing entries
+      countItems();
+      // Advance to the first item.
+      skipToWithoutCache(0);
+    }
+  }
+
+  return !file_error_;
+}
+
 auto MutablePlaylist::clear() -> bool {
   std::unique_lock<std::mutex> lock(mutex_);
+  return clearLocked();
+}
 
+auto MutablePlaylist::clearLocked() -> bool {
   // Try to recover from any IO errors.
   if (file_error_ && file_open_) {
     file_error_ = false;
diff --git a/src/tangara/audio/playlist.hpp b/src/tangara/audio/playlist.hpp
index ac62c82e..1e05e9c4 100644
--- a/src/tangara/audio/playlist.hpp
+++ b/src/tangara/audio/playlist.hpp
@@ -33,7 +33,7 @@ class Playlist {
   virtual ~Playlist();
   using Item =
       std::variant<database::TrackId, database::TrackIterator, std::string>;
-  auto open() -> bool;
+  virtual auto open() -> bool;
 
   auto filepath() const -> std::string;
   auto currentPosition() const -> size_t;
@@ -45,6 +45,10 @@ class Playlist {
   auto prev() -> void;
   auto skipTo(size_t position) -> void;
 
+  auto serialiseCache() -> bool;
+  auto deserialiseCache() -> bool;
+  auto close() -> void;
+
  protected:
   const std::string filepath_;
 
@@ -68,7 +72,7 @@ class Playlist {
    */
   const uint32_t sample_size_;
 
- private:
+ protected:
   auto skipToLocked(size_t position) -> void;
   auto countItems() -> void;
   auto advanceBy(ssize_t amt) -> bool;
@@ -79,9 +83,13 @@ class Playlist {
 class MutablePlaylist : public Playlist {
  public:
   MutablePlaylist(const std::string& playlistFilepath);
+  auto open() -> bool override;
 
   auto clear() -> bool;
   auto append(Item i) -> void;
+
+ private:
+  auto clearLocked() -> bool;
 };
 
 }  // namespace audio
diff --git a/src/tangara/audio/track_queue.cpp b/src/tangara/audio/track_queue.cpp
index ff24637b..05ac0b95 100644
--- a/src/tangara/audio/track_queue.cpp
+++ b/src/tangara/audio/track_queue.cpp
@@ -159,6 +159,13 @@ auto TrackQueue::open() -> bool {
   return playlist_.open();
 }
 
+auto TrackQueue::close() -> void {
+  playlist_.close();
+  if (opened_playlist_) {
+    opened_playlist_->close();
+  }
+}
+
 auto TrackQueue::openPlaylist(const std::string& playlist_file, bool notify)
     -> bool {
   opened_playlist_.emplace(playlist_file);
@@ -422,6 +429,9 @@ auto TrackQueue::serialise() -> std::string {
                                      cppbor::Uint{shuffle_->pos()},
                                  });
   }
+
+  playlist_.serialiseCache();
+
   return encoded.toString();
 }
 
diff --git a/src/tangara/audio/track_queue.hpp b/src/tangara/audio/track_queue.hpp
index 727b4be0..383c204e 100644
--- a/src/tangara/audio/track_queue.hpp
+++ b/src/tangara/audio/track_queue.hpp
@@ -76,8 +76,9 @@ class TrackQueue {
   auto currentPosition(size_t position) -> bool;
   auto totalSize() const -> size_t;
   auto open() -> bool;
-  auto openPlaylist(const std::string& playlist_file, bool notify = true)
-      -> bool;
+  auto close() -> void;
+  auto openPlaylist(const std::string& playlist_file,
+                    bool notify = true) -> bool;
   auto playFromPosition(const std::string& filepath, uint32_t position) -> void;
 
   using Item =
diff --git a/src/tangara/system_fsm/running.cpp b/src/tangara/system_fsm/running.cpp
index f065737b..227eac2c 100644
--- a/src/tangara/system_fsm/running.cpp
+++ b/src/tangara/system_fsm/running.cpp
@@ -214,6 +214,7 @@ void Running::react(const internal::Mount& ev) {
 
 auto Running::unmountStorage() -> void {
   ESP_LOGW(kTag, "unmounting storage");
+  sServices->track_queue().close();
   sServices->database({});
   sStorage.reset();
   updateSdState(drivers::SdState::kNotMounted);