Frank Cummings accepts a position, as the new captain of the old ship Sheridan, taking a classified cargo to the Ligurian system. Among his crew are old friends and strangers. The classified nature of the cargo means the owner has hired an unidentified agent to help ensure delivery. But the cargo has also attracted an assassin, trying to prevent delivery of the cargo. While Capt. Cummings tries to figure out who might be friend and who might be foe, the crew experiences a number of mishaps that might be sabotage or might just be the result of an old ship breaking down.