The Blood Barrier (1920)

Eugene Solari is fanatically jealous of his beautiful wife Enid. While on a mission for her father, she visits Major Trevor. Her husband finds out and, enraged, rushes to Trevor's house. Enid tries to beat him there to warn Trevor, but is too late--when she gets there Eugene shoots her and then kills himself, but not before he names Trevor as his killer. Trevor is arrested for his murder. A foreign agent, wanting a secret formula that Trevor is in possession of, kidnaps Enid and gets word to Trevor that he will clear Trevor's name and return Enid to him if Trevor will give him the secret formula.