*Spoilers* Why is Hugh the only one who didn't have...
... a "Red Room"-room? And he couldn't get into it on the night they returned while Steve could.
Olivia said "we" are the key, so does it exclude Hugh?
He saw Nell's ghost at her memorial service and his wife when the Forever House model had been destroyed, so he wasn't excluded from the effect the house had on the family, so why hadn't he been "digested" by the house (neither in the past nor in the present)?
Maybe the house didn't let him in in the present as he wanted to "steal" the children, but before that he never had his own "stomach room".