Knock-knock-knock. No, that's not creepy at all. Being in a spaceship twelve light-years from home and having someone knock on the door is totally normal.

Outstanding novel! This book delivered in every way and I may have enjoyed it more than The Martian because of the relationship Grace develops.

Andy Weir unloads a lot of science in this book but it never feels cumbersome. What is the nitrogen level in an atmosphere? What spectrum of light can humans see? How about a sprinkle of physics? These scientific references are added in fairly often but work to enhance the story and avoid turning it in to a scientific article.

There is also plenty of science fiction in here but it doesn't seem out of place with current technologies and capabilities.

Weir allows his characters to get in to a bind and requires them to combine MacGyver skills and critical thinking to bail them out. I didn't know what to expect with each chapter and had some pleasant surprises and twists. There were even a few moments where I laughed aloud, which is an impressive feat.

You and I found each other. That's something.

The relationship between Grace and Rocky was surprisingly wholesome and emotional. For me this is where Project Hail Mary excels over The Martian (but yet both get four stars). This added a very enjoyable layer in to the story and allowed for a nice blend of comedic relief against the impending doom of the mission.