GR translation: a sacrament of hands in every last turn each hand must produce

[Mike Jing]

P211.10-22   Fine for back there. But not in here, tapping on her bare
shoulder, peering in at her European darkness, bewildered with it,
himself with his straight hair barely combable and shaven face without
a wrinkle such a chaste intrusion in the Himmler-Spielsaal all crowded
with German-Baroque perplexities of shape (a sacrament of hands in
every last turn each hand must produce, because of what
the hand was, had to become, to make it all come out exactly this way
. . . all the cold, the trauma, the departing flesh that has ever
touched it. . . .) In the twisted gilt playing-room his secret motions
clarify for him, some. The odds They played here belonged to the past,
the past only. Their odds were never probabilities, but frequencies
already observed. It’s the past that makes demands here. It whispers,
and reaches after, and, sneering disagreeably, gooses its victims.

What exactly is the part in the parentheses about?