| Name | First Aired | Runtime | Image | |
|---|---|---|---|---|
| S01E01 | Checkpoint, Part 1 |
March 13, 1972
BBC One
|
25 | |
| S01E02 | Checkpoint, Part 2 |
March 14, 1972
BBC One
|
25 | |
| S01E03 | Checkpoint, Part 3 |
March 15, 1972
BBC One
|
25 | |
| S01E04 | Checkpoint, Part 4 |
March 16, 1972
BBC One
|
25 |
No artwork of this type.
No artwork of this type.
No artwork of this type.