Countdown is the penultimate entry into the Survivalist franchise; and is the series at its best. The sub-oceanic rift hurdles towards a tectonic plate. When it connects, a chain of supervolcanic action will end the world. The Trans-Global Alliances scrambles to find a solution, perhaps landing on one that would require nuclear warheads to be used underwater. How ironic that the weapons that once ended the world now have the potential to save it.
The Rourke-Rubenstein clan has managed to rescue Sarah, who underwent brainwashing to make her think John shot her. This dynamic is interesting and plays out in the climax. To shocking effect. Additionally Zimmer puts in motion plans to ensure his and Martin's immortality.
Countdown has all the elements of what makes this series enjoyable. Action, soft political dynamics, loveable characters, and most importantly the perseverance of good versus unspeakable evil. 5 out of 5 stars for pulp fans.