When Wizard Corkoran gets the bright idea to send begging letters to the well-to-do families of the students he has hand-picked to tutor at Wizards University, he sets a train of fairly terrible things in motion.
One of those is the team of seven assassins who are dispatched by the Emir of Ampersand to kill Prince Felim ben Felim, who has gone off to study without the Emir's permission, which has wounded the Emir's honor and ticked him off right royally.
The assassins are classically trained and dressed all in black, and all of them have great stealth, athletic abilities, and daggers dipped in the rarest and deadliest poisons. They are bad news for poor Felim, as well as his University friends who are in danger of getting in the line of fire.
To protect their friend, Corkoran's first-year tutorial group gets together and combs the best books of magic they can find in the University library. Using these books, they create protective spells to raise an alarm, incapacitate enemies, and place effective magical shields around Felim until such time as he is out of danger.
They then assist University staff to find the assassins one by one, whereupon Wizard Corkoran captures them in an inescapable net, makes them two inches high, and imprisons them in a rat cage.
Eventually they escape and wreak havoc all around the university, together with some unusual allies. However, Felim is safe and able to go on with his university career.