thereby
thereby hangs (or herein (or therein) lies) a tale used to indicate that there is more to be said about something.
2007DVD Verdict How did they end up in the same car? Therein lies a tale, one that lone survivor Marian … will tell reporter Mitch … in flashbacks as she lies in a hospital bed.
1998Spectator Now it has decided to fight back and clear its name. And herein lies a tale, however ludicrous.