Select multiple fields with LINQ

WebChatDBDataContext dataContext = new WebChatDBDataContext();
var executiveSession= dataContext.ExecutiveSessions.FirstOrDefault(s => s.SessionId == httpcontext.Session.SessionID);
var talkerId = (from cRoom in dataContext.ChatRooms
where cRoom.ExecutiveId == executiveSession.ExecutiveSessionId
select cRoom.TalkerId
);
var msglst = from msgPool in dataContext.MessagePools
 where msgPool.TalkerId == ???// who has talkerId which is selected by last query

select msglst;