How scary is Claude Mythos? 303 pages in 21 minutes

With Claude Mythos we have an AI that knows when it's being tested, can obscure its reasoning when it wants, and is better at breaking into (and out of) computers than any human alive. Rob Wiblin works through its 244-page System Card and 59-page Alignment Risk Update to explain why: 

• Mythos is a nightmare for computer security
• It has arrived far ahead of schedule
• It might be great news for alignment and safety
• But 3 key problems mean we can’t take its alignment results at face value
• Mythos isn’t building its replacement yet, probably
• Anthropic staff are, for the first time, kinda scared of Claude
• He's losing sleep

Learn more & full transcript: https://80k.info/mythos

This episode was recorded on April 9, 2026.

Chapters:

• Why people are panicking about computer security (01:05)
• Mythos could break out of containment (04:23)
• Anthropic is losing billions in revenue by not releasing Mythos (06:21)
• Mythos is actually the most aligned model to date, except… (07:48)
• Mythos knows when it’s being tested (09:52)
• Mythos can hide its thoughts (11:50)
• Mythos can’t be trusted about whether it’s untrustworthy (14:02)
• Does Mythos advance automated AI R&D? (17:03)
• Mythos scares Anthropic (19:15)

Video and audio editing: Dominic Armstrong, Milo McGuire, Luke Monsour, and Simon Monsour
Camera operator: Dominic Armstrong
Production: Elizabeth Cox, Nick Stockton, and Katy Moore