This is Pedro. Pedro has just fallen off the side of a valley, right on the edge of the watershed, after some nasty weathering - freeze-thaw weathering and solution to be exact. Pedro has landed in the source of a river with some awful bumps and cracks. He started to roll across the river bed.
After Pedro rolled across the river bed (traction) because the river wasn't strong enough to pick him up, he witnessed some water pushing air into tiny cracks in the river banks (hydraulic action). Then he heard a deafening pop sound that echoed throughout the river. Pedro had never heard a noise as loud as that!
Pedro continued to roll across the river bed when he saw some other rocks that looked like him. They were also roller across the river bed. But Pedro was heading right for them. He couldn't stop! Pedro bumped into them and started to rub against them (attrition). Pieces of him were breaking apart!
After Pedro met the rocks, he felt rounder and his edges were gone. Then Pedro started bouncing up and down in the river (saltation). He felt a stinging pain in his back. There were acids attacking him from behind (corrosion)! He was in pieces now after that attack. Then Pedro slowly started to float up...
Pedro was floating across the river (suspension) when he saw some round rocks from below bumping into the river bank (abrasion). Bits of rock and soil were flying everywhere! As he floated past the rocks, he started to have a stinging pain in his back. The acids were attacking Pedro again!
After the acids attacked Pedro again, he was so small, you couldn't see him! He was floating across the river (solution) when he saw fish and seaweed swim past him. There was more sand than before, and he was closer to the river bed, even though Pedro was floating. In the distance, Pedro could see the sea! Freedom at last. But what happens next?