The Third Mushroom, by Jennifer L Holm. Random House, 2018. $22.99 ages 8 and up

"We sit around the kitchen table playing a board game that involves castles and ghosts and giant spiders that eat you. It looks easy at first glance, but it's actually pretty difficult. At random points in the game, spiders kill you, and you have to go back to the beginning of the board. "This is ridiculous!" my grandfather shouts when it happens to our team for the third time. "We have to start over again?" My mom teases him. "But, Melvin, surely you've learned ... "

I previously wrote a post about The Fourteenth Goldfish which I very much enjoyed. In this pleasing sequel we meet up with Ellie and her grandfather Melvin again. Ellie is a scientist and middle grader. Her grandfather is also a scientist, and a grumpy 77 year old in the body of a teenager because of an experiment he made to reverse the aging process.

This is another middle grade novel by Jenny Holm, written with heart and  humor. She gives such presence and honesty to her characters. Ellie is interested in seeing if a movie date with her best friend Raj might lead to romance. It does not. But, it does reconnect her with Brianna, an old friend, and that is a good thing. Ellie and Raj remain best friends. That is just one small part of this story sure to please fans and find new ones for Ms. Holm.

When the grandfather she admires and loves returns after some time away from the family, she invites him (who is said to be her cousin while at school) to be her science fair partner. Initially reluctant, he does agree and they set out to use a jellyfish for their work. It turns out that the creature they find has actually been eaten by the jellyfish ... an axolotl. As they work together on the project they make many discoveries. Ellie learns about other scientists and their accomplishments, a pet dies, and they make some discoveries about medical science that are sure to give pause. Those events assure discussion among readers, and provide opportunity for some critical thinking. An experiment gone wrong often teaches more than scientists ever thought they would learn.

Backmatter includes an author's note about the discovery of penicillin and the importance of scientific study. That is followed by a list of resources, and then a series of notebook-like entries about the scientists mentioned as Ellie and Melvin take their learning to a new level. 

Humorous and thoughtful, I like learning more about Ellie, a character for whom I have great admiration.

"... I wish someone would invent a new category of books: on friendship, The books could have their own section in the bookstore, like fantasy or history. They could call it Friendmance or maybe Friend Fiction.
     Because friendship is as important as love. You can have a bad day with a friend. You can eat barbecue chips with them. You can count on them to help you survive middle school.
     Just like in the natural world, friends come in all different genus and species. There are best friends, like Raj. And there are old friends, like Brianna, who are important, too."

https://youtu.be/IRxRVlHjNu0