You and Tamru, arm in arm, start the swim through the frosted crystal caves. Each piece of crystal was grown from volcanic hotspots, then worked and slotted together by some of the oldest merfolk crystal-shapers. Every few years, new pieces are added or old pieces adjusted. The result is a maze of twisty passages, with larger main roads that fork off into tributaries of private caves. The pattern serves the needs of traffic while keeping a fresh, cleansing current running through the city.
You easily navigate through the passageways: up, left, right, straight. It would be confusing if you hadn't navigated every path hundreds of thousands of times before.
You look at Tamru. Even though you're so much faster and stronger than him, he still kicks his legs while swimming in an effort to help push himself along. You're always a little uncertain if slowing to match his pace is accommodating or patronizing. Tamru notices you looking at him and smiles politely, obviously expecting a conversation. Do you bring up anything?