Tiassa is structured in three novellas, spanning ten years of Vlad's life, with some interstitial matter. The first novella, "Tag," is a caper story set in the early part of the series and is told in the Chandleresque, hard-boiled style that characterized the first few books. The middle novella, "Whitecrest," is a story of political intrigue set during Vlad's exile, told with expert timing and a lot of wit. The final novella, "Special Tasks" is told in the style of The Phoenix Guards and its sequels, a highly mannered, absurdist adventure story in the mode of Alexander Dumas. All three revolve around a maguffin, the silver tiassa (an animal like a winged tiger), fashioned by a mischief goddess and possessed of hinted-at mystical powers.
Tiassa showcases Brust's great versatility and the vast sweep of the Vlad Taltos books. Like all the books in the series, it's a cracking adventure yarn, a finely tuned piece of literary storytelling, and a frustrating reminder that the adventures of Vlad Taltos will take many more books to complete, and these books aren't finished, and you will have to wait and wait and wait to read them.
I've written glowing things here about the Vlad books many times before. If you haven't read the Vlad books yet, start here and then go on with this list (I wouldn't recommend starting with Tiassa). Meanwhile, get writing, Brust! We want the next one!