S5·E4 Bad Medicine

More drug-related homicides are occurring. Pembleton is still relegated to desk duty and now so is Kellerman. A federal grand jury investigation is being conducted that goes back to the time when Mike was in the arson unit. Frank is still not taking his medicine and getting ready for the range test. Brodie moves out of Munch's place and into Bayliss'. Lewis finds out that the witness to his drug homicide has been brought downtown. He goes after him and meets Stivers, a female detective in narcotics. Lewis's witness points toward Luther Mahoney as the initiator of the contract. They go to find the executor, who's been executed. Stivers pages Mahoney and he comes in for questioning, but they can't make a case that Danvers thinks will stick. Frank misses a passing grade on his test by four points.