Jack's dilemma

[Freddy]

5444535A5A360 wrote: ...  This trick was unadvertedly discovered by me in The Pirate Invasion and used by you in The Hanging Gardens of Babylon.  It was you that used it first with the key combination.

Feel free to open THGoB in the builder to see how it works 

The reason your Jack cannot move on after he retracks his steps back to the right is that there is one (the last yellow door) door still closed as Jack did not have a key for that door.  And now he cannot reach the lever that helped him

slide

through that door.

I'll look into this in September and try to find a solution to prevent a JS in this situation.

It may surprise you that I didn't answer this post yet. Only today I was able to get through the very first grey door puzzle of my own section.
:o : >

And that was o so necessary because I was in urge for the lantern! With that lantern I understood why I didn't get through the adjacent dark room without any light. From then on things went more smoothly. Arrived at save 1 with 0 lives left.
:-[

See pic 1 from a map and pic 2 with my 2nd saving on the end of my section( with all money found).

Without peeping in the builder I saw the difference between the issue in JD and in HGoB. In the latter there is a way back upwards for picking up forgotten keys.