The Avengers.S06E29.Requiem

Tara finds herself attending a Requiem service for Mother, when Steed inaugurates a one-man witness protection scheme for a key witness against Murder International: taking the witness to Fort Steed, a hiding place supposedly known only to him. However, agents bent on murdering the witness boobytrap Steed's apartment. When the bomb explodes, Tara is severely injured and Mother is killed. Now Tara must find Steed in time to warn him.
-----------------------------------------
Teleplay by Brian Clemens
Directed by Don Chaffey
----------------------------------------------
Guest Starring: Angela Douglas, John Cairney, John Paul, Denis Shaw, Katya Wyeth, John Baker