These fiendishly clever mystery novels have spawned pop culture icons, anime and a museum. And, best of all, honkaku plays fair – you have the clues to solve the crime

After a day of joyous wedding celebrations, a bloodcurdling scream echoes into the night. The newlywed bride and groom are found dead in their bed, stabbed with a katana sword, now thrust into the snow outside. Their bedroom was locked from the inside, and there is no way the murderer could have broken in to do the deed, let alone escaped without leaving a trace. How was this impossible crime committed?