Book #20 of the Papa Pontivy series.
The escape of a notorious spy named George Blake from Wormwood Scrubs prison was the talk of the town. Papa Pontivy and Bernard Newman are asked to help find out how the escape happened. They will discover a prolific jail-breaking gang is at work and the pair will have their work cut out for them bringing the team down. Marshall is very much behind asking for Pontivy and Newman to assist and he plays a major role in the matter.