I have tried to open the door for 3 days. I never hear a click, I don't know where on the keyhole to put the end of the key. After key glows red do I try to put it in hole while it is still glowing or do I try to use it when it is not glowing.
I may have to ask you to send me a way to skip this problem.
Sincerely,
jtiffin

Hi Jtiffin,

You should definitely hear a click. Yes, put the correct key in the keyhole while it is glowing red. You won't actually see the key enter the hole -- just hear the click.

After using a key, right click to release it back into inventory before picking up the next key.

Also (this is important!) - be sure that you have the colour coded paper in your inventory which gives you the clue for opening the door. To get this, you have to left-click on the numbers painted on the ceiling in the water tunnel, and Carol will note them down.

The door will open automatically when all the keys have been correctly used.

Thanks
Rushes for your help. It took 5 more tries & finally I got the door open & managed to finished the game. I don't know what made the door open, I never heard a click, but it's over.
Thanks again,
jtiffin

Great that you got through, hope you enjoyed the game.