Sounds like the start of a tongue twister....
digital only Frostgrave expansion, Sellsword. This 12 page expansion allows warbands to hire a new character type, the Captain. The Captain chooses his own equipment, gains experience and has some special abilities to use, adding a bit more variation to things. You just need to be careful when giving him magical items as he won't give them back, even if he leaves!
When recruited, he gets to pick from a range of special (one use per game) tricks, each granting bonuses to an action. Some of these occur before dice rolls, others afterwards. The author had some concerns about how people would take this as it is not the traditional skills that some people will be expecting, but I think they should work well. My favourite one so far is Leadership. This allows you to activate three additional soldiers instead of one when you use the Group Activation skill. That should allow for some serious beatdown, or a surprise surge towards an objective. New tricks can be learned by spending xp instead of gaining health or will, and you can use any number of tricks in one go.
Besides all the rules for the Sellsword, we also get three new missions, one new item (Book of Null), one new Bestiary item (Nullmen) and a new Wizard sheet that includes a space to track the captain.
It says in the intro section that this is entirely optional and should be discussed with your group first, but as Joseph discussed in his blog on Monday, this looks like something that will become core to everyone's experience as it adds some real interesting dynamics. All in all, pretty good for £3.