Simplify the following text for a Grade 4 native English-speaking person.
Original: A dove descends from heaven , and , taking the place of the swan at the head of the boat , leads Lohengrin to the castle of the Holy Grail .
Simplified: A dove comes down from heaven , and takes the place of the swan at the head of the boat . It takes Lohengrin to the castle of the Holy Grail .