McNulty (Dominic West) is assigned to a team of outcasts assigned to probe drug lord Avon Barksdale's (Wood Harris) operations.
McNulty's detail tries breaking the code on the gang's pagers; Bell teaches D'Angelo how to train lookouts.
A tip-off prompts arrest, but Avon and Stringer grow suspicious; another witness to the Grant murder emerges.
Rawls' demands create strange allies; Wallace and D'Angelo wrestle with their consciences; Omar turns witness.
The detail suffers a setback; Russell and Bunk return to Philadelphia in search of evidence; Brother Mouzone talks with Stringer Bell regarding their agreement.