A ring of payroll check forgers led by Thad Docker obtains counterfeit (but genuine-looking) payroll checks from a printer named Scovill, who has recently taken over the heretofore legitimate Nonpareil Printing Company. Dan Mathews and Officer Johnson painstakingly eliminate other possible sources of the bogus checks and set a trap by asking area merchants to place an inconspicuous (but unique) marking on each of their legitimate payroll checks. When their stake-out of area merchants catches one of the counterfeit check-passers in the act, Docker panics and attempts to flee the area. However, he unwittingly leads Dan and Officer Johnson back to Scovill's printing shop, where an armed confrontation ensues.
—Sam Spear