taverner

First with “Military Wives” and a brief yet spellbinding appearance in “Fleabag,” but most importantly with “Slow Horses,” in which she plays MI5 second-in-command Diana Taverner alongside Gary Oldman’s sidelined but still tricky operative Jackson Lamb.

There are many things to love about the series, but Scott Thomas’ performance as Taverner is among the top three.

While everyone around her is losing their heads, her Taverner can look directly into the roiling abyss and calculate a way, if not to fix it, then certainly to cover it up.

Taverner is certainly not the hero of “Slow Horses.”

Whelan, even more than Lamb, has tested Taverner’s patience this season, which has been a challenge for Scott Thomas, who is so invested in keeping her character calm, cool and collected that from the first she has demanded a no-profanity policy for Taverner.