An uneasy friendship turns into a dangerous game when the love of a woman is on the line.

Just when Tom Breckinridge has decided to propose marriage to Diana Marshall, a rival has come out of the woodwork: Reginald Popplewell, a childhood neighbor of Diana's, and now heir to a viscountcy. Diana's father much prefers Reginald, but Tom believes Reginald has something to hide.

When Mrs. Marshall invites Tom to a house party at their home near Brighton, Tom finds even more to dislike about "dear Reggie," but Diana won't hear a word against him and goes so far as to wring a pledge from Tom that he will make a friend of Reginald. Knowing just how risky it can be to befriend a con man, Tom will discover to what lengths he is willing to go to win Diana.