Signs ending explained · Cinespective

What happens

Morgan's asthma attack closes his lungs, so the creature's poison gas doesn't reach him. Merrill swings his bat, spilling water that burns the creature. Graham finds his faith again and puts his priest's collar back on.

The last image

Graham, back in his clerical collar, stands in the house with his family as the aliens have gone.

Two readings

1 · A sign from aboveColleen's last words, Morgan's asthma and the water glasses line up too perfectly to be accidental.

2 · Pure coincidenceEach detail has a plain explanation, and Graham chooses to read meaning into luck.

What it says

The film doesn't prove aliens or God. It shows that believing is a choice about how to read what happens to you. Graham's grief took his faith, and he gets it back by seeing a pattern.