Secrets being revealed early

I was wondering, I'm planning on revealing a shocking secret in the second chap of my fic.
And I was wondering... Is that a good idea?
After I reveal it, will people just guess what's going to happen and stop reading?
I mean, take a look at the Kirby anime; Kirby and Meta Knight's secret was revealed in the Fourth episode and 4kids tv was able to air it all the way up to the 100th episode, just like in Japan.

Will the same case be for Me?

Keep in mind that just because something happens in a television series doesn't mean it'll work for you. (Personally, I didn't particularly care for Kirby: Right Back At Ya either way. *shrug*) It depends completely on the secret and the circumstances.

In general, you want to save your big guns for later chapters. That way, you'll build up mystery and suspense before finally unleashing the shocker to an audience who's stuck around to try to piece things together. It's not so much an issue of the audience figuring out where the fic will go from there so much as it is an issue of whether or not the audience will feel that revealing a big secret too soon leaves the rest of the work "soft" -- because they're expecting something bigger later on and may or may not get it. That is, whatever happens in the first few chapters tends to be small potatoes compared to the chapters after that. Reveal something early, and you're going to have to come up with something bigger later.

Of course, sure, you can try to pull it off, but be careful by making sure what happens after that doesn't make that point in the story feel anticlimactic.

Look at it this way. I revealed a shocking secret in the beginning of my Fic (by Pokemon standards). But I also reveal an even more shocking one later, so it evens out.

You can reveal a dark secret about one of the main characters that the other characters don't know, but the audience does. This way, you're still building suspense as the audience waits to see the reaction of the other characters when they discover the secret.