It's a basic challenge of fiction: Find a plausible way for an ordinary person to plunge into an extraordinary situation.

That's what Your Honor, the miniseries starting at 10 p.m. Sunday on Showtime, does so well. Aided by the subtle skill of Bryan Cranston (top), it keeps sinking deeper into a pit.

Such stories are best if the protagonist starts with a small sin he wants to hide. He takes a car for a joyride, unaware there's a body in the trunk; sneaks into an apartment, unaware it's a drug house; cheats on his wife, unaware that the object of his lust is obsessive.

In this case, there's an extra layer – a widowed dad is desperate to help his son.

The story starts on the anniversary of the day his wife was killed. The early minutes – at times, almost wordless – fling his teen son into a crisis. The boy reacts shakily; people do that sometimes, as anyone knows who has studied Chappaquiddick.

Now the dad (Cranston) must help. He's a respected judge with a good sense of people. He also occasionally makes mistakes, something that happens when lies wobble on top of each other.

This is a story of subtle missteps. It's smartly written by Peter Moffat (The Night Of) and skillfully directed by Edward Berger (Deutschland 83, Patrick Melrose). It's also played perfectly by Cranston and Hunter Doohan as his son.

Surrounding them are some potent women, played by Hope Davis and Margo Martindale. Both characters have had an offspring die suddenly; in opposite ways, both are relentless.

Martindale's character doesn't even arrive until the fourth episode, but she becomes an instant force. That episode offers an extraordinary confluence – an unscheduled dinner, linking people who know different shards of the truth.

It's a great scene, and as far as I can go. The first four episodes were available for review; six more remain, with lives quaking.