The Camelot Code: Geeks and the Holy Grail (The Camelot Code, 2)

Sophie must embark on her first official mission as a companion in the action-packed sequel to The Camelot Code!
In the second book in the Camelot Code series, Sophie is now tasked with protecting the spirit of King Arthur throughout the ages, so it's no surprise when she and Stu get sucked in to another Arthurian adventure: get the Holy Grail into King Arthur's hands so he can drink from it and recover from a deadly illness.

It's not easy, especially since Merlin's apprentice, Emrys, has accidentally turned the Grail into a gassy, fire-breathing baby dragon. And Merlin is the only one who can change it back. But Merlin's on spring break in modern-day Las Vegas (at the Excalibur, of course). And Sophie's super-popular (not to mention super-annoying) future stepsister, Ashley, has invited herself along for the ride.
From sneaking a baby dragon through airport security to the ultimate showdown with the sorceress Morgana, deep in the land of Faerie, this new Camelot Code adventure will test not only the two geeks' courage, but also their very friendship. Spring break just got epic!