“Yeah, well, you’re lucky you have the same last name as your mom,” I tell her. “My mom was Valerie Gómez until she got remarried to my stepdad. Now she’s Valerie Jasper. What a stupid name.”

Mercedes sulks. I sulk. We say nothing.

“Now I’m the only Gómez.” I stop my swing and think, Except—

“Except you’re not the only Gómez,” Mercedes interrupts my thoughts like a mind reader. “Frank Gómez. Mattie Gómez.”

“So, you knew about me? You knew my mom was married to him? I mean,” I pause, trying to find the right words, “I, um, didn’t know anything about you.”

Mercedes lets out a short laugh like a bark. “Obviously. You want to hear what I know?”

My phone pings just then. It’s my mom:

When will you be home? Can you help Kenny with his math homework?

“I have to go pretty soon,” I say.

“Listen,” Mercedes says. She plants her feet so her swing stops moving. “You can go. It doesn’t matter to me. I just thought you might want to know some stuff. Since you seem to know nothing. It’s your life, too.”

“Don’t get like that, Mercedes.” I sigh. She’s so touchy. “Just tell me everything.”

But she doesn’t say anything at first. She jumps off the swings like she’s going to leave. Instead, she paces and then circles the swing set. She’s like a lion in a cage at the zoo.

Mercedes clears her throat and starts talking really fast. “Mom travels all over the world for her job, and she met him when she went to Bogotá. That’s in Colombia, if you don’t know. She was there for a few months. They were, like, boyfriend and girlfriend. He showed her this picture of a baby girl and said he was divorced. Anyway, they broke up, obviously. By the time she got back to San Francisco and realized she was pregnant with me, he was deep in the jungle—or maybe it’s the mountains?”

Mercedes stops circling.

“As far as I know, he’s been there ever since. She said he never even met the one daughter he did have, so there was no point in contacting him—even if it was possible to contact someone in the jungle.”

“What was he doing in the jungle?”

“He’s a famous anthropologist.” She says this like it’s the most obvious thing in the world.

“He studies dinosaurs?” I ask. Lucas is obsessed with dinosaurs. He has these little plastic figures and he knows the names of all of them even though he’s only five. And he’s constantly leaving them on the floor in the hallway, where we trip on them.

“How do you not know this? He’s an anthropologist.”

“Oh, wait,” I say. “An archaeologist is the one that studies dinosaurs.”