Can Black save the 4 stones (bamboo)?

I am white. At this point black started to think and think and finally timed out.
Don’t understand why. Can anyone enlighten me?

It may depend on what is going on outside the area you have shown, e.g. are the two white stones on the upper left side potentially alive. Black may be able to connect ( the bamboo joint ) but in doing so looks like he may have a shortage of liberties.

[ I see now I can get the whole position… will have a look ]

Ok… if black tries to capture the marked stone, by stopping the connection, he gets into a snapback. White will push in the other side, and then throw a stone into the bamboo joint and capture in snapback. So the marked stone cannot be captured.

On the other hand, black can I think save the bamboo joint by playing where White pushes in the above variation. White has to connect, and then Black can connect as well.

He can save all of them ( I did put variations) with a weird connection in the bamboo joint

@Groin, @GeorgeBarwood
Thank you very much!