NEEDLE IN A TIMESTACK is based on a story by popular science
fiction author Robert Silverberg. Though he has been a prolific
author for the last seventy years(!), little of his work has been
filmed. The only major exception is THE BICENTENNIAL MAN (based on
"The Positronic Man").

This film has a jazzy score and a diverse cast (and a touch of food
porn), and is divided into three sections, representing three
timelines, centering on Nick, Janine, and Tom. Each starts in the
boardroom of a wealthy corporation with somebody is giving a talk
that sounds like double-talk. In the middle, a "time shift" (or
"phase"--they seem to use the terms interchangeably) makes reality
change. Apparently changing timelines is "time crime" but that
seems to happen anyway. Nick thinks someone is trying to change
his timeline in specific.

Throughout the film people's lives get screwed up just the same way
they have been with time shifts. Things get entangled, and one
character says, "We can't change the past; we can just clean up the
future a little bit." (It sounds a bit like relationship
counseling.) Also, people tend to speak in aphorisms (like that
one, or "Happiness is the only thing more fleeting than time.")

Nick signs up for a service called "Past Protect" which presumably
saves your memories from this timeline in case a time shift changes
something. Oddly, memories from one timeline last for a few hours
when the timelines shift, but gradually fade. Past Protect has
somehow lost most of his memories but he can remember Janine for a
while. The idea in general creates situations similar to those in
TOTAL RECALL, though in this film Nick is looking for someone to be with him forever in love rather than trying to have an adventure.

The mechanism for the time travel is not clear, though the body (or
a body) does go back in time (rather than just inhabit the person's
earlier body). Not surprisingly, Nick's attempts to "fix" things
have a somewhat different effect. (One nice touch is a close-up of
Nick's hand in each segment, revealing his different marital
statuses.)

Released in theaters 10/15/21. Rating: high +1 (-4 to +4), or
6/10.

Film Credits:
<https://www.imdb.com/title/tt7099280/reference>

What others are saying:
<https://www.rottentomatoes.com/m/needle_in_a_timestack>

--
Mark R. Leeper