Double the twins means double the detective power! Meet the Fourth Floor Twins, two sets of clever siblings who share an apartment building and a serious knack for solving puzzles. When they notice their neighbors acting incredibly strange, their sharp detective instincts immediately kick into high gear. The neighbors' nephew is sneaking around, behaving suspiciously, and carrying mysterious packages. Could he be up to no good? The twins are absolutely convinced that a sneaky crime is taking place right under their noses. Teaming up to gather clues, follow the suspects, and piece together the evidence, these four friends are determined to uncover the truth. But can they solve the bizarre case of the fish snitch before they get caught snooping? Packed with teamwork, humor, and plenty of suspense, this exciting chapter book is perfect for young readers who love a great neighborhood mystery!