Thanks Gandalf for your quick reply.

However my case is slightly different. Allow me to be more precise with the scenario. The hazard is guarded by yellow sticks on one side (nearer to the ball) and red sticks on the other (nearer to the green). The ball flew over the hazard, hit a tree, and went back into the hazard.

Thus, did the ball enter the lateral hazard just because it went back into the hazard through the red sticks (in which case, the ball will be played 2 clubs length where is entered the water) or would it be considered it did not pass the hazard at all ?

It should be either one or the other. I understand either way there is a 1 stroke penalty but where do you think the ball should be played after the penalty is taken?

Thanks