Friendship

In The Lost Hero, three demigods named Jason, Piper, and Leo made their first visit to Camp Half-Blood, where they inherited a quest:

Seven half-bloods shall answer the call,
To storm or fire the world must fall.
An oath to keep with a final breath,
And foes bear arms to the Doors of Death.

Annabeth is terrified. Just when she's about to be reunited with Percy - after six months of being apart, thanks to Hera - it looks like Camp Jupiter is preparing for war. As Annabeth and her friends Jason, Piper, and Leo fly in on the Argo II, she can't blame the Roman demigods for thinking the ship is a Greek weapon.

After their last laser-beam-filled adventure, Lily, Jasper, and Katie have flown off for a restful stay at a distant mountain lodge. What a coincidence when they find the lodge teeming with characters from other middle-grade series novels, including the dashing Manley Boys and the boy-crazy Cutesy Dell twins. And when the Hooper Quints go missing, it looks like their vacation is over.

When Brian and Gregory receive an invitation to stay at a distant relative's strange mansion, well, they should know better than to go. Once there, they stumble upon The Game of Sunken Places, a board game that mirrors a greater game in which they have suddenly become players. Soon the boys are dealing with attitudinal trolls, warring kingdoms, and some very starchy britches.

You can learn a lot about life by observing another species. That's what Humphrey was told when he was first brought to Room 26. And boy is it true! There are always adventures in the classroom and each weekend he gets to sleep over with different students.