"Avengers" #19 by Jonathan Hickman and Leinil Yu is the series' second tie-in to the "Infinity" crossover -- although if you're coming aboard hoping to seamlessly drop into the story, you may be due for a rather rude awakening.
As a writer, Hickman is one of the best. His stories are tight and dense, and he throws concepts at the page like he's got a sack of them at home with a rapidly approaching expiration date. The problem is that in doing so, he tends to give each one equal weight. Sometimes an offhand remark is just an offhand remark; other times, it's a key plot point. Fully realising worlds in this way is one of his greatest strengths, but as a reader -- especially a new one -- it can feel like a weakness. You have to work hard to keep up, and when the payoffs aren't due for months, that can understandably put people off.
On its most basic level, there's clear idea to the story here. The Builders have captured Captain Marvel for interrogation, while a galactic congress of races attempts to devise a strategy to ward off the Builders, unaware that one of their number isn't particularly on-message. That synopsis suggests a dialogue-heavy issue -- and rightly so -- but those who are on-board with Hickman's hard sci-fi approach will be pleased to know that it's well-paced and full of plot and character. Just don't expect action in the traditional sense.
Artistically, Yu is a great choice for "Avengers" #19. During his run on "Secret Invasion," readers learned how great he is at drawing both alien warfare and hugely-crowded scenes with a huge number of varied designs -- a trait that continued in this issue. It helps that Sunny Gho's colors are fantastic -- the vivid and broad palette really sells the wonder and spectacle of these intergalactic characters and situations.
As an adjunct to "Infinity," though, this does feel like an optional piece of the puzzle despite its top billing. True, it explains what the Avengers are doing as a result of "Infinity" #2, but it doesn't have anything to do with Thanos or Earth, which is what many will see as the core of the "Infinity" story. "Avengers" #18 was recapped in half a page of "Infinity" #2, so it's reasonable to expect "Avengers" #19 to get similar treatment in #3.
Its importance might change further down the line, but those who turn up for the crossover will probably get the sense that this is more of a continuation of the current "Avengers" story than a particularly important "Infinity" tie-in. It's an appreciated strategy for crossovers: telling a story that isn't mandatory to understand the event but also isn't just spinning its wheels between panels. For the moment, it's the best of all worlds. Let's hope that continues.