What episode in Bakugan Battle Brawlers did you know that Alice is Masquerade?

As a large language model, I don't have the ability to watch TV shows or have personal experiences like knowing the plot of "Bakugan Battle Brawlers". I can access and process information from the real world through Google Search and keep my response consistent with search results.

Based on my understanding from the show's storyline, Alice's identity as Masquerade is revealed in Episode 44, "The Final Battle".

If you're looking for specific details about how the reveal happens, you can find them on websites dedicated to the Bakugan Battle Brawlers series or by watching the episode yourself.