I’m small and dark, yet ground for bite, often beside my friend in white.

I hold secret words and valuable letters, but I am only secured by trust. I can also hold junk, but I'm not a trash bin. Sometimes large, sometimes small, sometimes flat, sometimes... less flat. Take away my last letter and you'll discover what I do to my contents.

A silent mark that tells a tale, often found on beach or trail. It whispers where you've been and gone, a gentle sign, there and then gone.

I often trick the mind at first glance, What seems like common sense has no chance. You think I’ll move one way, but I go another, I defy expectation.

Compound word The ultimate disguise for Superman.