Mister Max:The Book of Lost Things

I don't know if it can be considered a clue at this point in the novel, but the two characters mentioned in Max's father’s note are from two different plays... something that make his grandmother suspicious. So when Grammie notices the line from a Midsummer Night’s Dream, a play about illusion, the words could be a hint that Max’s father was trying to get a message to him. His parents might have met with foul play.