I think Rudra definitely trusts Paro. Otherwise he would never leave her in the room alone with his father. Let alone the entire night. He would have suspected the lep she brought, just like he suspected Laila's poisonous haldi.
He definitely has a trick up his sleeve. I'm sure he knows it's Sumer and Kaki behind all of this. Hence, ek theer mein do nishane. He'll be reassured that Paro is innocent, because he knows she'll agree to marry Sumer. And then the truth behind his father's condition will be out somehow too.
I haven't been this excited about a show in the longest time. I have my thinking cap on after EVERY single episode. 😆
Truly commendable to the actors and the entire team. 👏