Greggs, returning from abroad with a large consignment of precious stones, thwarts the first attempt of Gentleman Joe and his accomplice to rob him at his hotel, but they follow him aboard the train the when he is alone on the observation platform they attack him, and a struggle ensues in which Greggs is finally thrown to the ground from the speeding train. Helen, riding through the hills in an auto, comes upon him before Joe and his pal can alight from the train, Greggs gives her the diamonds and tells her to speed away and rush help back to take care of his injuries. The thwarted conspirators hold up a following auto and speed after Helen. Rounding a dangerous curve, Helen momentarily glances back, and the next moment her auto is dashed to splinters over an embankment, while she jumps in the nick of time, Apparently at bay, a wrecking train approaching on the bridge above offers a means of eluding her pursuers. She climbs a telegraph pole, and the trainmen, seeing her fanatic signals, swing out the huge derrick and she whirls through the air to the train. Joe and his accomplice, facing capture, jump into their auto and start to flee, but the chain from the derrick descends and hooks under the hood of the auto, swinging it into the air. The trainmen soon descend and make the pair captives.