Two days passed,
Rex went back to Ochyra University after the meeting with Wesley Atkins.
The poison that somehow gets into the refreshment is Edward's doing, Rex already told him to take the vial behind the flower pot and intercept their drinks.
It's Rex's plan all along, he needs the Reed Family to be the one that gets the blame.
If Rex and the others were to shelter the blame of the Atkins, then the problem will not be over making his parents stay in the Cluster Domain longer.
Rex also already gave one of the spellbooks to the Atkins Family.
The spellbook that he gave to Wesley is a replica that he pay for quite a sum to the system, Rex finds out that the system can scan the spellbook and copies it.
Because of that, the real spellbooks will be given to Reed while Wesley holds one replica.
He also holds one other replica that will act if, in two months' time, he can't free himself from the Atkins Family.