Smartass Achievement

[Solemn Gong]

I've played through the entire game twice, and I loved it. Wadjet Eye knocks it out of the park every single time.

I'm one of those guys who has to get every achievement for every game, and I'm having trouble with the Smartass achievement. I've exhausted all conversation topics with Denby, left-clicked and right-clicked everything in the room several times, used every inventory item with everything in the room, entered and exited the room several times, and tried to exit the room after leaving the gas on. The achievement still won't unlock. Is there something I'm missing?

[Yuri]

Grundislav has already explained all the actions you need to do!
You can see it in my Achievement guide: http://steamcommunity.com/sharedfiles/filedetails/?id=641118708

[Solemn Gong]

Perfect, this is exactly what I needed. Excellent guide. Thanks, Yuri!