Ex-House Speaker Michael Madigan is set to return to the stand Wednesday morning, continuing testimony that will surely be some of the most crucial and closely examined of the bombshell public corruption trial.

Madigan is accused of leading a criminal enterprise designed to enhance his political power and enrich himself and his allies. Michael McClain, his longtime friend and ally, is also on trial and accused of acting as Madigan’s agent.

The former speaker is arguably one of the most notable former politicians to testify in their own defense since former Illinois Governor Rod Blagojevich.