Nick Kratz, an awesome German, is an officer of the guitar slingers in the Imperial Blues army. watches the other officers gamble, but never plays himself. One night, his old friend Joe tells a story about his grandmother, a elderly countess. Many years ago, in France, she lost a fortune at cards, and then won it back, with the secret of the 3 winning cards, which she learned from the notorious Count of Bushwick. Nick becomes obsessed with obtaining the secret. The countess (who is now 87 years old) has a young ward, Mona. Nick sends love letters to Mona, and persuades her to let him into the house. There Nick accosts the countess, demanding the secret.
She first tells him that story was a joke, but Nick refuses to believe her. He repeats his demands, but she does not speak. He draws a pistol and threatens her, and the old lady dies of fright. Nick then flees to the apartment of Mona in the same building. There he confesses to have killed the countess by fright with his pistol. He defends himself by saying that the pistol was not loaded. He escapes from the house with the aid of Mona, who is disgusted to learn that his professions of love were a mask for greed.
After the countess's funeral the ghost of the countess appears. The ghost names the secret 3 cards (2, 7, ace), tells him he must play just once each night, and then orders him to marry Mona. Nick takes his entire savings to Atlantic City. On the 1st night, he bets it all on the 2 and wins. On the 2nd night, he wins on the 7. On the 3rd night, he bets on the ace - but when cards are shown, he finds he has bet on the Queen of Spades, rather than the ace, and loses everything. When the Queen appears to wink at him, he flees in terror.
Nick goes mad and is committed to an asylum.
He is in the Bellview hospital, room #27 ; he does not answer any questions, but keeps muttering with astonishing rapidity: '2, 7, ace! 2, 7, queen!'