"This chap's a spy, that's a dead cert.," continued Danvers. "The other fellow is an accomplice and brings him grub."
"But you said that the quantity was insufficient," protested Ralph. "Your theory doesn't hold good."
"Hanged if it does," admitted Danvers, "It's a regular mystery. No doubt——"
A gentle cooing above their heads caused the men to look up. Flashing the light they discovered that nesting in a niche in the end wall was a birdcage. It must have been placed there since the building was partly demolished by shell-fire.
Standing on another man's shoulder one of the piquet handed down the cage. Within were four carrier pigeons.
"The chain of evidence is complete," declared Danvers. "Bring those birds along—and this one, too," he added, indicating the still struggling prisoner.
"A very good night's work," commented the C.O., when the two subalterns had made their report. "Two birds with one stone, by Jove! All right, carry on; we'll have this gentleman tried by court-martial in the morning."