Spoilers....
For those who didn't understand.
First daina pays the guy to kill Camilia and when she finds out the job is done by seeing the blue key she gets totally paranoid and and it is shown that she kills herself but actually she doesn't... She went asleep and dreams what we see first two hours and after she wakes up director goes to flashback and shows us what actually the people daina saw in dream are in real life. The old couple and the disgusting creature shown are imaginary characters created by daina's mind which generally induces fear.