The BBC have released the synopsis for the series finale, "The Name of the Doctor":
Clara is summoned to an impossible conference call, alerting her that the deadly Whisper Men are closing in on Vastra, Jenny and Strax. Someone is kidnapping the Doctor’s friends, leading him toward the one place in all of time and space that he should never go. It’s a deadly trap that threatens to unravel his past, present and future...
Executive produced by Steven Moffat and Caroline Skinner
Directed by Saul Metzstein
Written by Steven Moffat
Produced by Denise Paul
Series produced by Marcus Wilson