Rae (Leverage) will first appear as Siobhan McDougal, aka the Silver Banshee, in Episode 16, "Escape."
The Banshee is a vengeful spirit of a fallen Gaelic heroine. She's accidentally released from the underworld, and takes out her vengeance at an unassuming country bed and breakfast. Guess who just happens to be staying at the B&B? Lois (Erica Durance) and Clark (Tom Welling).
Rae joins the line of DC heroes and villains being added to Smallville this season, including Icicle (Wesley MacInnes), Dr. Fate (Brent Stait), Hawkman (Michael Shanks), Star Girl (Britt Irvin) and Amanda Waller (Pam Grier).