The moment Spencer meets Hope the summer before seventh grade it's something at first sight He knows she's special possibly even magical The pair become fast friends climbing trees & planning world travels After years of being outshone by his older brother & teased because of his Tourette syndrome Spencer finally feels like he belongs But as Hope & Spencer get older & life gets messier the clear label of "friend" gets messier too Through sibling feuds & family tragedies new relationships & broken hearts the two grow together & apart & Spencer an aspiring scientist tries to map it all out using his trusty system of taxonomy He wants to identify & classify their relationship but in the end he finds that life doesn't always fit into easy-to-manage boxes & it's this messy complexity that makes life so rich & beautiful