Splinter Cell: Chaos Theory is free to download via Ubisoft Connect PC, and you've got until 9am local time on Thursday, November 25 to claim your copy.
As Ubisoft explained in an announcement post, as long as you download Chaos Theory within this limited freebie window, you'll get to keep it forever and play it whenever you want. You can claim the game directly through Ubisoft's post provided you already have a Ubisoft Connect account set up, and to play it, all you need to do is install the launcher for the publisher's storefront/social club hybrid.
Giveaways like this pop up on Ubisoft Connect fairly regularly, so even if Chaos Theory doesn't trip your trigger, free is free, and it's worth having an account set up so you're prepared for future freebies.
If you like keeping your PC games in one place, and that place also happens to be Steam, you can alternatively get Splinter Cell: Chaos Theory on Steam for $2.50 right now. Coincidentally, it's on sale for 75% off until Monday, November 22.
Chaos Theory was originally released in 2005, and its depiction of information warfare circum 2008 is oddly charming, even quaint, given today's technology. This back-of-the-box blurb from its Steam page is also a gut-punch of aged nostalgia:
"As good as real - Never-before-seen graphics technology offers the best visuals on any system yet. Advanced physics engine allowing ragdoll physics, particle effects, and perfect interaction with the environment."
As good as real. May the universe give us even half the confidence of mid-2000s video game marketing.
Sadly, Chaos Theory's multiplayer was retired in 2016, but upcoming indie stealth game Spectre hopes to recapture and build on the legacy of its Spies vs Mercs mode.