Thursday may 11th 9PMHouse, Wilson and Cuddy are playing poker at a Casino Night fundraiser for the hospital.Their game is interrupted by a doctor who tells Cuddy that six-year-old Ian Alston has been brought into the ER. He has bloody diarrhoea and is developing coordination problems. Cuddy says she’ll see him later, but House uncharacteristically decides to leave the game to check on the boy.He soon realises that Ian's brain is losing control of his muscles, and goes back to the benefit to assemble his team. In the diagnostics lab, House tells the junior doctors that they are dealing with two patients with identical symptoms: Ian and 73-year old Esther, who he treated 12 years ago.She had Ian's exact progression of symptoms, but died of kidney failure – which he predicts will be Ian's next symptom – in less than a day. The team is sceptical, figuring that Ian merely has food poisoning. House considers Erdheim-Chester, a rare blood disease that attacks the vital organs. Chase points out there have only ever been 200 people who have suffered from the condition, but House thinks Esther was case number 201 and laments the fact that her family refused an autopsy. Tests for the disease come back negative, but in the meantime Ian’s kidneys have begun shutting down – he is reaching Esther’s third and fatal symptom. An MRI shows that the pituitary gland at the base of Ian's brain is also failing, just as Esther's did. The team finds House breaking into the commissary to get some coffee. He says that the next stop in the disease's progression will be the liver, and orders them to give Ian every drug they can think of that will protect it. Later, Chase informs House that Ian's liver is fine, but his blood cell count is abnormal. Oddly, House is encouraged. This is a new symptom, different from anything Esther experienced. But suddenly, Ian begins gasping for breath, which is the last symptom Esther developed before she died. With Ian now on a ventilator, the team again tries to analyse the mystery disease’s relentless progression.

Wilson suggests they should take a closer look at Ian's heart valves and Chase spots a small mass. House immediately insists on a performing a biopsy, during which Ian goes into cardiac arrest. After an eight-minute struggle to revive him, House is able to shock him back to life.

Back in the office, the team begin brainstorming when Cuddy barges in, having been alerted to Ian’s plight by the Alstons. She accuses him of giving the boy brain damage and of still being obsessed with Esther's case after 12 years. She orders him to stay away from Ian. But as soon as she leaves, he carries on regardless and hands Cameron the mass they extracted from Ian's heart.

However, there is only enough tissue to test for three diseases, and the team think Ian could be suffering from one of seven. As the gambling continues downstairs, can House and his team bet correctly on the right disease, knowing that Ian's life is the stake? And will House finally be able to lay the demons caused by not saving Esther to rest?