Lacie, Bruce and Wayne are the antagonists in the Goosebumps book Don't Go To Sleep.
They are in an elite squad called the Reality Police. Their job is to make sure nothing interferres with the course of reality.
In The Book
When Matt has enough of his tiny room, he sneaks into the guest bedroom one night and falls asleep. Little does he know that a Reality Warp is in the room and every time he wakes up, he's in a different reality (ex: One day he's a high-schooler, the next he's an 8 year old.)!
When Lacie appears in the different realities, she acts kind and gentle towards Matt (usually while acting like another student). However, when Bruce and Wayne appear, they act more aggressive and chase Matt and yell "We're gonna get you!"
In one reality when Matt is a lizard-like monster, Lacie leads Matt away from an angry mob and through the woods, only to lead him to Bruce and Wayne.
They then tell Matt that he is stuck in the Reality Warp. When Matt says that maybe he could get un-stuck if he were to sleep back in his regular bed, the three decline his thought and say the only solution is to put him to sleep. Permanently.
As they lock Matt in a room while they make the sleeping potion, Matt falls asleep and becomes a squirrel. He then runs out the barred window which he can now fit through and escapes.
A few days past, with the Reality Police hot on his trail, but he finally gets back to his bed at his real house and falls asleep. The next day................................ things are back to normal! Matt is so happy.
At the end of the book, Matt's mom gets him a birthday present. The present..... To move Matt from his tiny bedroom to the much bigger guest bedroom. Matt screams.
Lacie - Lacie is a very kind and gentle human being who tries to comfort Matt when she tells him that he would have to be put to sleep permanently.
Bruce and Wayne - Bruce and Wayne are more aggressive charcters that threaten Matt every time he makes a smart remark.
Even though Lacie is far younger than the other two (12 years old) she seems to be the leader of Bruce and Wayne (17). This is shown when Bruce and Wayne threaten Matt and she tells them to "Ssh" in which they do what she says.