Step into the trenches with the Cajun Pawn Stars as they set their sights on a rare WWI military periscope rifle. Will Jimmie ambush the seller with a once in a lifetime offer or will lines be drawn for an epic standoff? Then, a local resident known as Bayou Bob hopes to sell his massive engine from the 1890s called "The Mechanical Marvel." Can the guys turn their curiosity into cash or will they churn out more questions than answers? And later, Johnnie is shocked to learn a 1950s military field phone also doubled as an electric torture device. Will his hair be standing on end to make a great buy or will negotiations get overcharged and fizzle out?