and then the waves crash onto the beach and swish it all away, and all that's left is mush and a few wet mounds of sand.
(the waves; crash; onto the beach; T:then) (that; 's left; ) (all that's left; is; mush and a few wet mounds of sand)
the waves that all that's left
crash 's left is
onto the beach T:then
mush and a few wet mounds of sand