Suru

Katie, overcome by grief after losing her son Joel, desperately seeks meaning and is eventually led to an ancient ritual her son was studying before his death. Following a series of increasingly unsettling breadcrumbs she believes that her son might still be alive in a parallel universe. As Katie's obsession grows, her relationship with her husband Noah, who's also struggling with the loss, falls apart. With nothing to lose Katie follows Joel’s footsteps and performs the ritual.
After waking up she sees signs that she's traveled into a universe where her son is still alive. Things also seem to be back to normal with her husband. But, just as life seems to be going well, it again falls apart, as she struggles against slipping back into her universe - the reality she dreads.