Then the dog chimed in. “And one of us always says something completely random! RUTABAGA!”

The horse and the lion glanced at the dog.

“Dude,” said the horse.

“We’ve talked about his,” said the lion.

“CARBURETOR!” barked the dog.

Even Annabeth seemed at a loss for words. “Um—”

“You must now face our challenge!” cried the horse. “Or else—”

Fortunately, we were saved fromor else. The door opened on its own, all three panels folding together as the knockers yelled, “Ow! Stop that! POOP DECK!”

Standing in the doorway was a ginormous hellhound.

Seeing a black Labrador the size of a rhinoceros, with bloodred eyes, a slobbering maw, and daggerlike fangs, my first instinct was to give her a big hug. I couldn’t help it. She looked so much like my old friend Mrs. O’Leary.

Then I reminded myself that Mrs. O’Leary was an exception among hellhounds. Most of them tolerated demigods only as appetizers.

Grover reacted first, which was probably better than me giving the dog a surprise hug.

“Hi, I’m Grover!” he said. “Um, do we need to finish the door-knocker challenge, or…?”

The hellhound barked with such force it parted my hair down the middle.

“I see.” Grover turned to us and translated. “This is Hecuba. She says to ignore the door knockers. They haven’t worked properly since the school closed down.”

Annabeth frowned. “School?”

“I think that’s what she said.” Grover paused. “Although that particular kind of bark can mean a lot of things. School. Kennel. Pee spot.”

I was glad I hadn’t had to learn animal-speak for my school’s foreign-language requirement. I’d barely been able to master numbers and colors in Spanish, even with my friend Leo Valdez as a tutor.

“WOOOF!” Hecuba barked again, her eyes fixed on me.

Grover looked troubled. “Uh, I don’t think so.…” He faced me. “You’re not salmon-flavored, are you? She says you smell like you’re salmon-flavored.”

Annabeth covered her mouth, trying not to laugh.

I added one more thing to my mental list of stuff to thank my dad for. Apparently, I smelled like Purina Catch o’ the Day to hellhounds. I wondered if I should reevaluate why Mrs. O’Leary liked me so much.

“No, I’m just Percy,” I told the dog. “That’s my name. Not my flavor.”

“Also kind of your flavor,” Annabeth added. Then to the dog: “I’m Annabeth. Hecate asked us to watch you for the week?”

Hecuba tilted her head, the way dogs do when they hearwalkortreatorson of Poseidon for dinner. She barked a third time, and I realized her breath did in fact smell like salmon. I wondered if it was from the last demigod Hecate had invited over.

“Great, thanks!” Grover said. “She saysC’mon in.”

We followed the hellhound inside, leaving behind the muffled cries of the door knockers. “Wait! We work fine! PORK RINDS!”

Inside, a black marble foyer opened into a great room that reminded me of a medieval church. Not that I’d ever been in a medieval church, but I sawSpamalotonce, so I felt like an expert.

Carved wooden beams held up the peaked ceiling, which was painted black and speckled with silver constellations. Stained-glass windows lined the walls on either side, despite the fact that the townhouse was wedged up against other townhouses, so there shouldn’t havebeenany side windows. In the corners of the room, more stone gargoyles squatted on columns. Hanging from the central rafter was a massive candelabra—an iron wheel with lit candles that looked like it would really hurt when it eventually landed on me. (I’ve found that the more something could potentially hurt, the more likely it is to happen, and no, I’m not going to dwell on how depressing that is.)

Persian rugs covered the gray stone floor, all embroidered with scenes of tortured spirits. Four straight-backed mahogany benches faced the far end of the room, where a dais was set up with a lectern and a grand piano. Above that, affixed to the railing of a wraparound staircase, was a crossed pair of unlit torches.