Since its launch in the mid-90s, Audible has pretty much been the only game in audiotown—Michael Kozolowski called it “the undisputed market leader in audiobook production [with] the world’s largest audiobook store” after the Audiobook Publishers Association released this year’s annual report.

But as of this week, Google is officially jockeying to compete with Amazon (which acquired Audible in 2008) in the fastest-growing market in digital publishing. (According to the APA report, audiobook sales increased 33.9% between 2015 and 2016, raking in an estimated $2.1 billion.)

In a release published on Tuesday, Greg Hartrell, head of product management for Google Play Books, said Google Play audiobooks are now rolling out in forty-five countries and nine languages, allowing listeners to buy books individually at an affordable price. A cursory look at Google’s audiobook store reflects a range of $4.99 to $25.95 (which is actually kind of steep?) for featured titles.

It’s no stretch to interpret this one-off option as a direct challenge to Audible, which favors its monthly subscribers with discounts. As of this writing, Google is offering, for example, the audiobook of Michael Wolff’s Fire and Fury for $8.99 (plus a 50% discount on your first audiobook), while Amazon’s offering the same audiobook for $23.95, or $14.95 to Audible members.

Google audiobooks will also synch with Google Home (naturally) and “weave” across multiple devices — another function with which Audible has struggled.

It’s an aggressive move, and we can only expect that Amazon will respond aggressively in kind.