Michael Gladis Michael Gladis

Former Mad Men star Michael Gladis will guest-star on an upcoming episode of Leverage, TVGuide.com has learned exclusively.

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Gladis, who played beatnik copywriter Paul Kinsey for three seasons on Mad Men

, will play Reed Rockwall, a public relations expert in crisis management. He ruthlessly protects his clients, often going after and destroying their enemies.When one of Rockwall's victims turns to Nate (Timothy Hutton) for help, however, it will be the team that pulls out all the stops to bring Rockwall down.

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Besides his work on Mad Men, Gladis also voices Chief on Adult Swim's cop-show parody Eagleheart.  He has also guest-starred on Law & Order: SVU, House, Medium and The Good Wife.Leverage returns for its fourth season on Sunday, June 26 at 9/8c on TNT. Gladis is slated to appear in the season's third episode, which is titled "The 15 Minute Job."