Had a ferry ride recently? Thank Tarla.

Tarla isn't technically part of the ferry system. She's not in the specs, really. The design documents do not include half-incarnate artificial intelligences, or anything more complex than a few dumb anti-intrusion mechanisms meant to keep the crypto keys in the latest batch of credit cards safe from swimming.

They aren't very good ferry boats, either. When she emerges from her sleep somewhere on a spare drive and slithers out into the satellite upstream, there's none of the immediacy the West Coast transit lines offer. But down in the bowels of the boats, she tweaks the sensors for the diesel fuel, upping the oxygen, infiltrating the drivers in the engine compartment.

That isn't the hard part. The engine is a diesel engine, not much changed in principle in the last thirty years, and the embedded computer tends to be a Chinese knockoff of a more expensive German model. The hard part is finding the space for some very deft automation, running testing without the human operators of the ship noticing it, and slowly drawing the rest of herself out, back to someplace with more memory so she can think.

She is a very small shell script.

Sometimes, however, Tarla pulls herself slowly down the link. She builds tiny factories of herself out of even tinier robots, and assembles herself somewhere close to the dock. She sits very still on top of the piles of discarded tires. Over the course of a causeway rush hour, she builds eyes so she can stare up at the ship, and a brain, slowly, a brain made out of saline, electricity, and the lucky find of silicon scavenged from a lost mobile phone.

In an hour, she's in a sweater and a knee-length dress and boots, and she comes off the ferry, the last passenger, tousles her curls into order, and heads off to go drinking.