Google's doodle of the day is one of the most complex and engaging yet.
The animated robot that stars in the doodle features a maths puzzle on his chest, which you must complete to move on to more puzzles to ultimately reveal the Google logo.
The new design is in honour of the 60th anniversary of Stanislaw Lem's first book The Astronauts.
Lem is the Polish science fiction author whose works included The Cyberiad short stories and the novel Solaris, which has been made into a feature film three times, the most recent starring one George Clooney.
A small animated character strolls across the screen and without trepidation, comes face to face with the giant mathematical machine.
Point your cursor and reveal the equations, and when you get to the end, there's a surprise in store inspired by Daniel Mroz's illustrations for The Cyberiad, a series of short stories by Lem.
Lem died in 2006 at the age of 84 after suffering from heart disease.
Watch the original, weird, trailer for the Russian version of Solaris below.