It was back in 2008 when J.J. Abrams produced Cloverfield, a found footage film about a monster attack on New York City. The film was infamously promoted with an enigmatic teaser trailer, which simply ended with the date 01/18/08. 10 Cloverfield Lane had a similar veil of secrecy, with the film's very existence not being known until the teaser trailer for the film surfaced back in January.
It should probably be emphasized right off the bat that, despite the similar title, 10 Cloverfield Lane is NOT a sequel to the 2008 film. The best description of the film is that it is a standalone story that takes place within the same universe as Cloverfield. In fact, 10 Cloverfield Lane began as a completely unreleased film titled The Cellar, before it was rewritten to include some connections to Cloverfield.
The vast majority of the plot of the film takes place in the fallout shelter built by Howard. Howard claims that there has been an apocalyptic attack of the United States and that it is not safe to be outside. However, he is also a very intense and controlling individual, who believes that both Michelle and Emmett should be grateful that he has allowed them to share his hospitality. John Goodman demonstrates just how scary a person he can be at times and he really shines as Howard, who comes off as accommodating one minute, before making a violent outburst the next minute.
The whole story of Michelle's saga in the fallout shelter is solid enough that there didn't really need to be any direct connections to Cloverfield. In fact, it can be argued that such connections almost turns the film into a completely different movie at times, with it being quite obvious that they were the result of rewrites. I'm not sure J.J. Abrams felt the need to return to the Cloverfield universe nearly a decade after the film was released and didn't just let first-time director Dan Trachtenberg create what is already a pretty decent thriller. However, 10 Cloverfield Lane is still a film worth checking out.