Watch Shamus for Free: How to Stream the Movie Online at 123Movies. . New York private eye Shamus McCoy likes girls, drink and gambling, but by the look of his flat business can't be too hot. So an offer of $10,000 to finds some diamonds stolen in a daring raid with a flame-thrower is too good to miss. His investigations soon get pretty complicated and rather too dangerous. At least along the way he does get to meet Alexis.