The film was a Lifetime movie called "The House Sitter" — note that it's three words instead of two, though it's an oft-used title: IMDb.com lists a "Housesitter" (one word, no article) from 2007 ("Waitress Elise's dream to become a painter isn't going anywhere, unlike her ex Gerry's, so she eagerly accepts to house-sit a month the country estate eccentric gentleman Frank inherited), a "The Housesitter" from 2012 ("For more than a century an elite secret society from a prestigious New England university has engaged in a macabre rite of passage. Now, a rival they did not know they had has sent a killer") and another "The House Sitter" from 2015 ("A house sitter considers the possibility he may not be alone; after he starts hearing strange noises during the night"). The fact that this title has been used so often may explain why this one was originally filmed under the title "Welcome Home" — though it's cut so closely to the Christine Conradt format, albeit written and directed by others (Marcy Holland is the writer and Jim Issa — any relation to Darrell? — is the director), they might as well have called it "The Perfect Housesitter." It's basically the same-old, same-old Lifetime formula that's got pretty threadbare after they've been making these movies for over a decade. It begins with a confusing prologue in which a young woman and her boyfriend come to the home of her parents, from whom she's been estranged for years, and finds that they're seated at the dining table with their throats slit. Through most of the film I was unclear as to whether that was going to be the denouement we should expect from the main story or whether that was a crime committed by the title character similar to what she was planning to do to the other central characters.

The main characters are the Lawrences: father Kyle (Sean O'Brien), mother Sara (Kate Ashfield) — who speaks with an impeccable upper-class British accent throughout; presumably Kyle, whose own vocal tones are nasal American Midwest, met and married a British woman lo those many years ago — and their two daughters. One of them, Lauren, the older, died before the main action begins — she fell through the ice at a frozen lake where the Lawrences were vacationing — and the other, younger daughter Amy (Shelby Young) is alive but all too conscious that her parents considered her second-best when her sister was alive and still do even though she's now the only one they've got. Amy is dating a cute guy named Travis (Guyon Brandt) but draws back from having sex with him. The titular house sitter is Rebecca (Ashley Dulaney, who turns in a nice psycho performance, though these nice psycho performances are starting to impress me less and less simply because as a regular Lifetime watcher I've seen too damned many of them — indeed, as engagingly twitchy as Dulaney is, I think Young as Amy out-acts her!), who agreed to look after the Lawrences' home while the three of them went on some sort of business trip that ended early. Rebecca pleads with the Lawrence parents that she has no place to stay since the residents of the next house she's supposed to house-sit are still there and aren't planning to leave for a few more days. No problem, says Mrs. Lawrence (Mr. Lawrence is a bit more dubious, as usual in these productions); Rebecca can stay in their guest room — though Rebecca "accidentally" takes a wrong turn and ends up in the dead sister Lauren's old room, which the Lawrences have kept unchanged as a sort of shrine to her. Amy goes ballistic when she sees Rebecca pawing through her sister's belongings, but Rebecca apologizes in her best smarmy, mock-sincere manner. The House Sitter is a pretty ordinary example of the Lifetime formula, a bit below par because writer Holland and director Issa tread on the thin edge of risibility through most of the film and go over it a few times — though they do create some chilling moments, including the scene towards the end in which Rebecca is holding a gun on Amy and telling her she no longer belongs in the family, and Amy is somehow able to hold on to her composure in spite of this stranger "hooking" all her worst fears about her parents looking down on her and wishing it had been she who had died instead of her sister.

A grief-stricken family is still recovering from the loss of a daughter when a house sitter strives to manipulate the parents into accepting her as the deceased daughter's replacement. All hell breaks looks as the house sitter plots her dastardly deeds on the nice family.

The house sitter from hell goes by the name Rebecca. But a perceptive old lady working in the local antique store recognizes her as Clair, who was a house sitter for the Peterson family in a neighboring town. Mr. and Mrs. Peterson died in a house fire. Shortly after identifying Rebecca as "Clair," the antique deal is murdered.

Rebecca now settles in to the home life of a lovely couple, Sara and Kyle. Their daughter Amy was racing on the ice with her sister Lauren. When the ice broke, Lauren drowned. The family is still trying to cope with the loss, and Lauren's old bedroom is maintained as a shrine.

The most interesting character in the film is Amy, who has never come to terms with the guilt that she feels over her sister's death. She also believes that Lauren was the favorite of her parents, who subliminally blame Amy for the tragedy. On top of everything, Amy must now co-exist with an interloper who is angling to move in permanently with the family.

Rebecca tries to sell the family on a sob story about her own traumatic past and heroic struggle for recovery. For a brief stretch, Sara buys into Rebecca's story and begins to accept Rebecca as a surrogate daughter. But it is Amy who is relentless in getting to the truth. It is Amy who first recognizes that "something is not right" with Rebecca.

There were some loose ends in the film, including an explanation of why the death of the antique dealer did not raise the suspicions of the family. Another untidy plot element was Amy's boyfriend Travis, who is seduced and apparently murdered by Rebecca. Poor Travis was not even given a proper funeral in the film. But in the end, it is the memory of the close relationship of Amy and her sister Lauren that sustains her through the ordeal with Rebecca and leads her to triumph over the evil machinations of monster.