Following my previous post here is the quote from "Down in the Cellar".
"You musn't mind Bruce," he said gently."It's not easy to see a thing through, when you aren't sure what it is you're seeing. the others have seen some things, and heard. But you just had to go ploughing on doggedly, with no sort of reward,"...
"Kind Julia..." he said,"...and clever Andrew...and Deidre who sees too much...they'll forget all that they've seen...And you Bill, who have seen so little will remember everything."
It really is a very good fantasy read along the lines of Susan Cooper's fantasy series but with the humor of Nesbit's Bastable children. What a pitty its out of print.