enclosure / (variant of 閒|闲[xian2]) idle / unoccupied / leisure
闲
=
木
+
门
:
In her free time (闲) Marie Curie (xi) likes to sit in the anthill's kitchen (an2) to watch her trap door (门). She installed it right under a Christmas tree (木) so whenever someone puts a present under the Christmas tree, shortly afterwards it will fall through the trap door in Marie's secret chamber.