Slightly invisible
"Adults will recognize a spot-on portrayal of children's imagination games, while kids will recognize the underwater, outer space, and mountainous territories that their homes become every day through play." -- Kirkus Reviews Charlie and his friend Marv have invented an invisibility potion to help them find strange and tricky creatures, which they would prefer to do without Charlie's little sister, Lola, bothering and interrupting. But when Lola enlists a bit of help from her invisible friend, Soren Lorensen, it turns out that the strange and tricky creatures have met their match in one very resourceful, inventive little sister.