My version is that Alexander himself had his priests concoct a potion to take him to the underworld. Like Gilgamesh went after Enkidu, he would meet and resurrect his love Hephaestion. It was a task that only a god could do. Surely, he would come back victorious and the world would never doubt his godhood again? Alexander was not one to blink at bad odds.
I have puzzled over the three men in the giant raft on the green blue Euphrates. Who are they? They are not carrying bricks or bitumin. One seems a passenger on board sitting under a small shelter, while the other two pole. Is it Alexander setting out? Or perhaps it depicts me, facing away from, but in the shadow of, the tower, moving toward the yellow bank, soon to inspect the tower itself piece by piece?