.. How do I defeat the vengeful ghost on the roof?

After a short conversation with Paul, Rosa and Joey go to the roof to find the Countess in the process of strangling Charles. You have a moral choice to make here --

-- which may be taken out of your hands if you just hang around wondering what to do, so this might be a good point to save your game.

Now: to save Charles the murderer, or to let the Countess kill him? Either way, there's more to do after.

If you don't want to save Charles, just stand there and watch. It'll be over in a minute.

If you decide to save Charles, you can't attack the Countess, but you have something in inventory that has some meaning for her; it could serve as a distraction.

Quickly, use the lit blue cigarette on the Countess, and she'll drop Charles and come talk to you. But there's more to come.

After a short conversation, the Countess turns on Joey, rips the tie out of hands, and attacks him. Um ... what now? Joey can hold his own, but he doesn't have the ability to do anything permanent to the Countess. This is one for Rosa.

The cigarette is now useless. But there's something else in the scene that has some power over ghosts, and I don't mean the paper clip from the diner.

Pick up Joey's tie. He once said it was a metaphor, and it is, but it's also a tether that hauls ghosts out of the physical world. It would make a dandy lasso right about now.

As Rosa, pick up the tie and stand immediately behind the Countess. When she draws her arm back to strike at Joey, use the tie on her, and she's snagged. But there's one more problem!

Rosa doesn't have the strength to haul the Countess in against her will. You need some help from Joey, and quick, or the Countess will break free and it's all to do over again.

As soon as Rosa catches the Countess's arm, switch to Joey and give the Countess a good hard push (i.e., left-click/interact with her). Phew!