If the first den didn't make it clear enough, you're not alone in the facility - and something has clearly gone very wrong.

This den can be found near the three moving platforms, and you'll need to create a portal inside the room to check it out.

Several broken cameras, tins of beans, and insane ramblings scrawled onto the walls. Did I mention the numerous pictures of the companion cube, too?

In the 2000s, you could use it on aperturescience.com to find more lore - but all is not lost in the current day! Go back in time and see the website in all its 2000s-era glory with the Valve Archives or WayBack machine.

https://valvearchive.com/web_archive/aperturescience.com/

In version 1.07a, entering 'login' will prompt you to enter a username (to which you should use 'cjohnson'), and password (to which you should use 'tier3'.)

The 'cjohnson' login unlocks more commands than a regular login, but you can use any username and the password 'Portal', too. Either way, after logging in you can type 'help' or 'lib' for a list of commands and explore the lore to your heart's content!

2. 'Append', 'Attrib', 'Copy', 'Erase', 'Format', 'Rename' and 'TapeDisk' result in errors - either "ERROR 15 [Disk is write protected]", or in the case of 'TapeDisk', "ERROR 18 [User not authorized to transfer system tapes]."

3. The 'Interrogate' command prompts you to use a parameter. Doing so returns "ERROR 07 [Unknown Employee]", or "ERROR 01 [Illegal attempt to initiate disciplinary action]" if you aren't logged in as cjohnson.

4. 'Dir' prompts you to enter 'Notes' or 'Apply'; 'Notes' shows the timeline as mentioned above, while 'Apply' takes you through a funny 50-step form to become a test subject at the enrichment centre.

5. 'Play' prompts you to use a parameter. 'Play Portal' attempts to open a since-removed YouTube video, which the Half-Life wiki claims was a clip from David Copperfield's TV special "Tornado Of Fire".

6. A secret command, 'Thecakeisalie', can be entered to receive the message seen below alongside a short surveillance video. Pressing any key on this page also shows an inventory spreadsheet with entries for flour, thumbtacks, and what seems to be extra-large intubation equipment.

7. Using the 'Help' command without being logged in returns this message:

8. Using the 'Goodbye' or 'Logoff' command prompts GLaDOS to say 'Goodbye' and sends you to Steam.