Desilu accomplished an impossible mission by producing two immortal programs in color television's golden age. These programs aired on different networks but naturally involved considerable sharing of character talent and production skills. Filming locations and familiar buildings appear frequently like old friends in strange clothes. Even the background accompaniment is often indistinguishable.

The philosophy however between the two couldn't be more different. The optimism of Star Trek contrasts against the cynicism of Mission: Impossible, also highlighted by the emotional tone of expressive starship officers versus the sangfroid IMF. Both "crews" have an unquenchable desire to complete the mission and their professionalism was exceptional. Both Jims summon life-and-death loyalty from their subordinates into an unstoppable esprit de corps. James Doohan as Montgomery Scott must have inspired many engineers as did Greg Morris as Barney Collier. Scott and Collier are mechanists without equal (dare we say "miracle workers") but Scott was no stranger to strong mood and strong drink whereas except for the omnipresent cigarette Collier was as cool as they come.

Stories abound about actors crossing over from one set to the other during idle moments. Even a leisurely glance at the guest roster brought a gusher of overlapping talent:

Sharon Acker, Michael Ansara, Barry Atwater, Barbara Babcock, Lee Bergere, Paul Carr, Anthony Caruso, John Colicos, Joan Collins, James Daly, Gene Dynarski, Diana Ewing, Brioni Farrell, James Gregory, Sid Haig, Marianna Hill, Susan Howard, David Hurst, Steve Ihnat, Mark Lenard, Gary Lockwood, Jon Lormer, Barbara Luna, Bruce Mars, Ed McCready, Lee Meriwether, Ricardo Montalban, Charles Napier, David Opatoshu, Vic Perrin, Phillip Pine, Logan Ramsey, Madlyn Rhue, Percy Rodriguez, Joseph Ruskin, Alfred Ryder, William Schallert, William Shatner, William Smithers, Warren Stevens, Michael Strong, George Takei, Vic Tayback, Torin Thatcher, Malachi Throne, William Windom, and Katherine Woodville.

There's even William Shatner (as a guest) and of course Leonard Nimoy (as a star). One of the more interesting overlaps involves Bob Johnson, whose voice appears in "The Cage" dubbed over another actor ("There's a canyon to the left. We can land you there unobserved."). Johnson is far better known for his anonymous, disembodied voice appearing in the M:I episodes in the series' famous taped messages staging each mission.

Sure there are atrocious accents, improbable latex face masks, and the (intentionally?) hilarious quasi-Slavic language known as "Gellerese." Everyone smokes and has a gun that will likely shoot during the episode. But this is an undeniable classic. And above all else M:I has (excepting only the signature for TOS perhaps) the best musical theme ever written!