The Truth Hurts - S3.E18

In an effort to get the goods on the 73 Crew, Binghamton lures the boys into the hospital, under false pretenses, and has them injected them with sodium pentothal - Or 'truth serum' - Which causes them to tell him everything he wants to know. McHale and Parker must then work up a plan to get them off the hook, by literally giving Binghamton a dose of his own medicine.