The Tories had a 17 point lead at the start of April! They expected a landslide...
ETA: Context for those haven't been following (and why would you?). The PM decided to call a snap election (even though she'd said she wouldn't) in order to increase her mandate before the Brexit talks.
Result: She lost the mandate.
The Tories are still the largest party, but they don't have a majority and might form a coalition with the DUP (The Democratic Unionist Party - Northern Ireland). Giving them a majority of... two?
ETA: Things you may have missed... . F.ex. Theresa May stood (amongst others) against a bloke called Lord Buckethead. Sometimes I love British politics. :)