The Glee stars have launched a mysterious charity contest to help The Invisible Children foundation and fans who donate a minimum of $10 will get the chance to win a “super secret Glee experience,” says The Hollywood Reporter.

The duo is partnering with Omaze.com to raise money for the non-profitable organization and while it is not clear what the big prize will be, it is known that Omaze has rewarded other fans in other campaigns with set visits and meets-and-greets with stars. It is expected that the winner will be meeting McHale and Shum.

“We’ll have some special guests as well. We’ll have some friends, and some castmembers who I think are taking part,” confided Harry Shum Jr., “But we want to keep that a secret.”

“People related to the characters as being underdogs. We’ve been extremely fortunate that our fans have been so giving,” added McHale, “[We’re] hoping to help as many people as possible learn about Invisible Children.”

Omaze has organized many charity contests like this before. In this case, the donations are not tax deductible and the company gets to keep twenty percent of all the money raised, with the rest going to The Invisible Children.