public override void Execute(Relay server, Client client, Session session, Message message)
        {
            if (session != null)
            {
                throw new Relay.UnexpectedSessionException();
            }

            var sessionId     = Convert.ToUInt32(message.body);
            var targetSession = server.GetSession(sessionId);

            if (targetSession == null)
            {
                throw new Relay.UnknownSessionException(sessionId);
            }

            var newJSON = new JSONObject();

            newJSON.Add("session", targetSession.id);
            newJSON.Add("beat", targetSession.GetLowestClock());

            server.AddToSession(sessionId, client);

            logger.Warn("Told client to start at beat " + client.session.GetLowestClock());

            using (var stream = client.tcp.NewStream())
            {
                var msg = new Message()
                {
                    beat       = 0,
                    controller = (byte)KingdomsSharedCode.Networking.Controller.SESSION_INFO,
                    body       = newJSON.ToString()
                };
                logger.Trace(">> " + msg);
                stream.Write(msg);
            }
        }