This was an All Quentin And Amanda episode, with no Leviathans in sight.
It's a real stretch of my imagination for me to believe that simply seeing the portrait brought back Quentin's memory. The last time Quentin saw that portrait, it looked nearly exactly like him, and now I don't see anything of Quentin in it. It's just a random old man with bleeding wounds, painted in a style that does not look like Charles Delaware Tate's. I suppose, however, that we have to suspend disbelief and accept that Quentin does see himself and all his misdeeds in it. But why all the misdeeds? I remember remarking when Quentin was in the hospital that he was a pleasanter amnesiac than Jeff Clark was. Hasn't he done anything good in the past 70 years? Even if he couldn't remember it, the portrait would.
The accident that landed Quentin into the hospital must have been quite a severe one if the portrait couldn't heal his wounds right away. Bravo, Barnabas! Very neatly executed! And, returning to a previous issue: If the accident caused the amnesia, then the portrait was a little slow in dealing with it. Or was Quentin's proximity to the portrait needed for the power necessary to effect a cure? Or was the amnesia not physically induced but rather supernaturally caused by Leviathan power, which, as we have seen with Barnabas and Philip, does not necessarily have lasting effects?
When Sam Evans died, did he go to Mr. Best's hotel in his raincoat and sunglasses?