Matheson invents a formula for a particularly effective explosive which he thinks will put an end to all war - so there is some interesting foreshadowing of the moral debates over nuclear weapons in the early pages. A mysterious gang are after the formula, and kidnap Matheson. Adventures ensue.

First published in 1929, this was one of Fletcher's more thrillerish offerings, and reminded me somewhat of Buchan's The 39 Steps - though I personally didn't think this tale was as good, and didn't consider it one of Fletcher's better books.

Rated 3.5/5 and recommended for devotees of the genre. ( )