Mr Keen, Tracer of Lost Persons starring Bennett Kilpack, originally broadcast October 27, 1949, the cast of the Ruthless Murderers. A man just out of prison after five years had sworn to kill Mr. Keen. But Keen is saved by one of his secret inventions. Also Part 4 of a 5 part Yours Truly Johnny Dollar story, The Alvin Summers Matter, originally broadcast October 27, 1955. How to fall into a trap...in one easy lesson.