"Warehouse 13" has quite a selection of special guest stars for its upcoming sophomore season, including a minor "Firefly" reunion, a crossover with "Eureka" and a few established faces from the science-fiction genre.

Now, the series has another name to be excited about: David Anders.

Fresh off of stints in "The Vampire Diaries" and "24" this season, Anders has signed on for a guest role on the popular Syfy series. And, just like all his other roles, no one is really sure who he is or what side he is even batting for.

Described as a "calculating suspect with a deadly past and a dangerous connection to the Warehouse," Anders' character, Jonah Raitt, evaded capture by Warehouse operatives in the 1960s and now it is left to Pete (Eddie McClintock) and Myka (Joanne Kelly) to track him down.

The actor has developed a reputation over the years for playing ambiguous villains, appearing in "Alias" as the insidious Mr. Sark, playing Kensai in "Heroes" and, more recently, being revealed as the biological father of Elena in The CW's "The Vampire Dairies." He also had a limited role in the final season of "24" as a Russian mobster involved with a terrorist plot only to have a change of heart.

"Warehouse 13" became a surprise hit last summer, premiering to Syfy's best ratings in the cable channel's history. In addition to Anders, fans can expect to see appearances from Lindsay Wagner, Tia Carrere, Jewel Staite and Sean Maher, Neil Grayston, Faran Tahir, Rene Auberjonois, Paula Garces and WWE's Cody Rhodes.

"Warehouse 13" returns to Syfy on July 6 at 9 p.m. ET.