Possible Clues:

• Mind matter
• They'll get you thinking 26 across is for the most part accommodating those in the monastery
• They'll get you thinking what the headcase is presumably holding for those in The Joy
• They'll get you thinking of most of those from 1 down in prison
• They'll get you thinking of most of those in 21 down and 10 across at school
• They'll get you thinking of intelligence factions