A super-secret, off-the-books spy organization; a security-clearance starting at Top Secret and going up from there; an attack by giant squid during a thousand-foot dive while breathing an exotic gas; a cat's whisker escape from death during a three-day decompression-and that's just the first two chapters of Operation Ivy Bells, before the action really gets underway.

In a fast-paced, personal narrative, J.R. "Mac" MacDowell details a breathtaking series of events during a super-secret intelligence gathering operation at the height of the Cold War. Riding the nuclear submarine Halibut, Mac and his saturation diving team surreptitiously enter Soviet-controlled Sea of Okhotsk on a proof-of-concept mission. They install a tap on an underwater communications cable at 400 feet, and narrowly escape death when a storm snaps Halibut's anchor cables. They retrieve missile parts from a Soviet missile-test splash-zone, getting caught in a sonar-web set by the crafty skipper of an old Soviet diesel submarine. Mac's divers temporarily disable the sub, and Halibut escapes to Guam, dogged by the sub Skipper.

Having proved the concept, they return in a Halibut, outfitted with skids so she can sit on the bottom, to attach a 12-thousand-pound pod to the cable for future retrieval. In the missile splash-zone, they lock in deadly underwater combat with Soviet divers. With the free world at stake, they capture one and kill the rest.

Halibut's submariners and saturation divers finally return home without ever publicly revealing their crucial contribution to winning the Cold War, receiving an unpublicized Presidential Unit Citation.