Now, this is how you do a crossover.
In January 1965, CBS, seeing the ratings of its primetime game shows begin to fall, came up with a unique crossover event. Bud Collyer and the panel of To Tell The Truth, were guests on I've Got a Secret, and the final game of the January 11 episode was a hybrid of the two shows. Collyer co-moderates with Steve Allen, who'd taken over Secret nearly 7 months earlier from Garry Moore, and Truth regulars Orson Bean, Tom Poston, Kitty Carlisle, & Peggy Cass sit in with Betsy Palmer, Bill Cullen, Bess Myerson, & Henry Morgan. The flirting between Poston & Palmer is only the beginning of this bonding experience.
As it turned out, Cullen figured out the whole shebang, even if he couldn't vote in the Truth half of the game.
Cullen would, in fact, guest host Truth a few years later, when Moore was away, and, as documented previously, MC'd the 1976 revival of Secret as a summer replacement when the series returned to CBS.
Notice that Secret is credited as a "Telecast Enterprises" production, but with the usual Goodson-Todman crew (i.e. Gil Fates, Paul Alter, Chester Feldman, etc.). Hmmmmmmm.
Tomorrow, we'll look at how the Truth team played Secret after the on-the-job-training.