Note that 2 and 3 are not indirect questions.
It's just inverted word order, chosen for artistic affect. When you start with the adverb phrase, you invert.
Around the rock ran the squirrel.
Up the hill charged the army.
Behind the door stood the tiger.
"Normal" prose would be "She found out which door the tiger stood behind" or "But he could not know which door the lady was behind."