If the above sounds like your cup of tea, then alas you're too late as the society is no more
We existed in one form or another since sometime in the 1970s (or possibly even earlier - if you have proof of when the society was started, please get in touch) when a group of students at Royal Holloway decided that they would regularly get together to enjoy their shared interests in science fiction and fantasy. This group decided to call themselves IFIS - The Institute For Impure Science and became one of the many RHUL SU societies.
Once part of the student union (SU), things got a bit more formal and over the years we've had many different constitutions and committees. But that hasn't hampered us from still enjoying the things we love the most. We've built up a modest sized science fiction and fantasy library for our members to read. We like watching science fiction and fantasy movies and TV programmes. And we enjoy going on trips to conventions or shopping in London. Membership comes with all kinds of perks such as access to the society's Netflix account.
Alas, things came to an end in 2021.
There are a number of theories surrounding the origins of the name. One most likely suggestion is that it's taken from the stories written by R. A. Lafferty. An alternative is that it's meant to be science fiction backwards (obviously lacking the C though). Generally though, it's because it's meant to be different, fun and the acronym is a lot easier to say than what we are. As a society, we don't like to take things too seriously.
(Except when it comes to the correct pronunciation of our name, which isn't i-fis - we're not an Apple brand name. Instead pronounce it like if-fis)