diff --git a/history/__init__.py b/history/__init__.py
new file mode 100644
index 0000000..fddb6f8
--- /dev/null
+++ b/history/__init__.py
@@ -0,0 +1 @@
+"""Track IRC channel history and report on it for users."""
diff --git a/history/ircplugin.py b/history/ircplugin.py
new file mode 100644
index 0000000..4a8b6cb
--- /dev/null
+++ b/history/ircplugin.py
@@ -0,0 +1,142 @@
+"""Monitor and playback IRC stuff."""
+import logging
+
+import irc.client
+
+from ircbot.lib import Plugin, most_specific_message
+
+logger = logging.getLogger(__name__)
+
+
+class History(Plugin):
+    """Watch the history of IRC channels and try to track what users may have missed."""
+
+    what_missed_regex = r'what did I miss\?$'
+
+    def start(self):
+        """Set up the handlers."""
+        logger.debug("%s starting up", __name__)
+        self.connection.add_global_handler('pubmsg', self.handle_chatter, 50)
+        self.connection.add_global_handler('join', self.handle_join, 50)
+        self.connection.add_global_handler('part', self.handle_part, 50)
+        self.connection.add_global_handler('quit', self.handle_quit, 50)
+
+        self.connection.reactor.add_global_regex_handler(['pubmsg', 'privmsg'], self.what_missed_regex,
+                                                         self.handle_what_missed, 60)
+
+        self.channel_history = {}
+        self.channel_participants = {}
+        self.channel_leave_points = {}
+
+        super(History, self).start()
+
+    def stop(self):
+        """Tear down handlers."""
+        logger.debug("%s shutting down", __name__)
+        self.connection.remove_global_handler('pubmsg', self.handle_chatter)
+        self.connection.remove_global_handler('join', self.handle_join)
+        self.connection.remove_global_handler('part', self.handle_part)
+        self.connection.remove_global_handler('quit', self.handle_quit)
+
+        self.connection.reactor.remove_global_regex_handler(['pubmsg', 'privmsg'], self.handle_what_missed)
+
+        super(History, self).stop()
+
+    def handle_chatter(self, connection, event):
+        """Track IRC chatter."""
+        what = event.arguments[0]
+        where = event.target
+        who = irc.client.NickMask(event.source).nick
+
+        logger.debug("tracking message for %s: (%s,%s)", where, who, what)
+        history = self.channel_history.setdefault(where, [])
+        history.append((who, what))
+        logger.debug("history for %s: %s", where, history)
+
+        # for when we maybe don't see a join, if they talked in the channel, add them to it
+        self._add_channel_participant(where, who)
+
+    def handle_join(self, connection, event):
+        """Track who is entitled to see channel history."""
+        where = event.target
+        who = irc.client.NickMask(event.source).nick
+        logger.debug("%s joined %s", who, where)
+
+        self._add_channel_participant(where, who)
+
+    def handle_part(self, connection, event):
+        """Note when people leave IRC channels."""
+        where = event.target
+        who = irc.client.NickMask(event.source).nick
+        logger.debug("%s left %s", who, where)
+
+        # if they parted the channel, they must have been in it, so note their point in history
+        self._add_channel_leave_point(where, who)
+        self._remove_channel_participant(where, who)
+
+    def handle_quit(self, connection, event):
+        """Note when people leave IRC."""
+        who = irc.client.NickMask(event.source).nick
+        logger.debug("%s disconnected", who)
+
+        # find all channels the quitter was in, save their leave points
+        for channel in self.channel_participants.keys():
+            self._add_channel_leave_point(channel, who)
+            self._remove_channel_participant(channel, who)
+
+    def handle_what_missed(self, connection, event, match):
+        """Tell the user what they missed."""
+        who = irc.client.NickMask(event.source).nick
+        if event.in_privmsg or event.addressed:
+            logger.debug("<%s> %s is asking for an update", who, most_specific_message(event))
+            if event.in_privmsg:
+                total_history = []
+                for channel in self.channel_leave_points.keys():
+                    logger.debug("checking history slice for %s", channel)
+                    total_history += self._missed_slice(channel, who)
+                    logger.debug("total history so far: %s", total_history)
+                logger.debug("final missed history: %s", total_history)
+                self._send_history(who, total_history)
+                return 'NO MORE'
+            else:
+                where = event.target
+                history = self._missed_slice(where, who)
+                self._send_history(who, history)
+                return 'NO MORE'
+
+    def _send_history(self, who, history):
+        """Reply to who with missed history."""
+        for line in history:
+            self.bot.privmsg(who, f"<{line[0]}> {line[1]}")
+
+    def _add_channel_leave_point(self, where, who):
+        """Note that the given who left the channel at the current history point."""
+        leave_points = self.channel_leave_points.setdefault(where, {})
+        leave_points[who] = len(self.channel_history.setdefault(where, [])) - 1
+        logger.debug("leave points for %s: %s", where, leave_points)
+
+    def _add_channel_participant(self, where, who):
+        """Add a who to the list of people who are/were in a channel."""
+        participants = self.channel_participants.setdefault(where, set())
+        participants.add(who)
+        logger.debug("participants for %s: %s", where, participants)
+
+    def _missed_slice(self, where, who):
+        """Get the lines in where since who last left."""
+        leave_points = self.channel_leave_points.setdefault(where, {})
+        if leave_points.get(who) is not None:
+            leave_point = leave_points.get(who) + 1
+            history = self.channel_history.setdefault(where, [])
+            missed_history = history[leave_point:]
+            logger.debug("in %s, %s missed: %s", where, who, missed_history)
+            return missed_history
+        return []
+
+    def _remove_channel_participant(self, where, who):
+        """Remove the specified who from the where channel's participants list."""
+        participants = self.channel_participants.setdefault(where, set())
+        participants.remove(who)
+        logger.debug("participants for %s: %s", where, participants)
+
+
+plugin = History