'Highland Gardens' casts Jewel Staite and Chelan Simmons-- but they don't want you to know that

"Degrassi" spin-off, "Highland Gardens," has started production in Toronto, Canada, but it appears the cast is being rather secretive about their involvement in the 6-episode series.

As we reported a few weeks ago, Cassie Steele will be reprising her role as Manny Santos on the series centered around the titular Hollywood hotel where many Canadian actors live during pilot season. Well now it appears she has two new costars.

"Firefly's" Jewel Staite, who we recently shared would film a guest spot on "Supernatural," and "Kyle XY's" Chelan Simmons have joined the cast. However, the actresses seem to be trying to keep the details under wraps.

Why? We have no idea.

"Hey world: follow my new gorgeous and lovely co-stars on my new show I still can't tell you about: @ChelanLSimmons @cassandrasteele," Staite tells fans via twitter.

Maybe she can't spill the details, but Vancouver-based talent agency, Principals Talent was more than ecstatic to share Simmons' casting news on their Facebook page.

"A huge shout out to a close friend of Principals Talent CHELAN SIMMONS for booking a Series Lead on the new Canadian Series 'Highland Gardens'. So Proud and well deserved :)" says a post.

We're excited to see these two lovely ladies join the show, but we're left wonder-- what's the big secret?

(Update: It appears that while Cassie Steele will be one of the stars of "Highland Gardens," she will not be reprising her role as Manny nor is the show still considered a spin-off. Instead, she will be playing a new role of Abby, a naïve Toronto actor who is ready to fight to get to the top.)