The opposition believe Steed is responsible for the death of their agent Vinkel. Steed, however, had nothing to do with the murder and, as a show of good faith, agrees to a swap of partners with Keller in a bid to find the real killer.
| Creator | Sydney Newman |
|---|---|
| Actor | Patrick Macnee, Linda Thorson, William Lucas |
| Country | United Kingdom |
| Production | Associated British Picture Corporation |