Theory
Episode: 4x01 | Airdate: Sep 12, 1968
Episodes
Proof
Episode: 4x02 | Airdate: Sep 19, 1968
Bird of Passage
Episode: 4x03 | Airdate: Sep 26, 1968
See the Rabbit
Episode: 4x04 | Airdate: Oct 3, 1968
Take Them in Singles
Episode: 4x05 | Airdate: Oct 10, 1968
Red Herring
Episode: 4x06 | Airdate: Oct 17, 1968
Five Pairs O' Hands
Episode: 4x07 | Airdate: Oct 24, 1968
Minor Incident
Episode: 4x08 | Airdate: Oct 31, 1968
An Old Song
Episode: 4x09 | Airdate: Nov 7, 1968
Big Boats, Little Boats
Episode: 4x10 | Airdate: Nov 14, 1968
For a Rainy Day
Episode: 4x11 | Airdate: Nov 21, 1968
Assistance
Episode: 4x12 | Airdate: Nov 28, 1968
Equal Status
Episode: 4x13 | Airdate: Dec 5, 1968
Obstruction
Episode: 4x14 | Airdate: Dec 12, 1968
Going Quietly
Episode: 4x15 | Airdate: Dec 19, 1968
On Christmas Day in the Morning
Episode: 4x16 | Airdate: Dec 27, 1968
Departure
Episode: 4x17 | Airdate: Jan 2, 1969
Cross Reference
Episode: 4x18 | Airdate: Jan 9, 1969
Run for the Hills
Episode: 4x19 | Airdate: Jan 16, 1969
Pressure
Episode: 4x20 | Airdate: Jan 23, 1969
A Quantity of Gelignite
Episode: 4x21 | Airdate: Jan 30, 1969
Critical Path
Episode: 4x22 | Airdate: Feb 6, 1969
Persistence
Episode: 4x23 | Airdate: Feb 13, 1969
Second Chance
Episode: 4x24 | Airdate: Feb 20, 1969
How's the Wife Then?
Episode: 4x25 | Airdate: Feb 27, 1969
Right to Search
Episode: 4x26 | Airdate: Mar 6, 1969
Proved Connection
Episode: 4x27 | Airdate: Mar 13, 1969