Thicker than water / Bruce Hale ; with illustrations by Brandon Dorman.

Enhanced descriptions from Syndetics:

Just when Max Segredo learned that his father is still alive, he also learned that Simon Segredo was working for LOTUS, an evil spy operation that wants to take down the Merry Sunshine Orphanage (a.k.a. the School for S.P.I.E.S.) and take over the world. Now Simon is on the run from LOTUS, and Max's surrogate family at the orphanage is being threatened from without and within. LOTUS is trying to drive the school out of business, while the Ministry of Health is investigating an anonymous complaint about the orphanage. To top it all off, the trainee spies are riddled by fear and squabbling among themselves. Into this chaos strolls a mysterious billionaire who hires S.P.I.E.S. to steal a powerful mind control device. The fee for the job will help save the school, but there's a catch: they've got just three days to pilfer the device from an ultra-secure facility before LOTUS steals it first. Can the S.P.I.E.S beat their rivals to the prize before the orphanage doors close for good? In this action-packed sequel to Playing with Fire , it is impossible not to root for Max, a spy-in-training with mad skills, a spunky attitude, a way with the ladies (well, okay, maybe not so much), and a big heart.