My son LOVES spy gear. We have had good luck buying almost all of the items they make, some even more than once due to being played and loved so much. My son's favorite part of this set was the invisible ink pen. Unfortunately, the pen was gone a few hours after receiving it. We keep the house clean and tidy. We looked for him everywhere, even in crazy places, and couldn't find him. Our current theory is that just moments after the last use, some of the ink leaked, landed on the pen itself, and rendered it invisible. We hope Spy Gear will soon release a GPS tracking product that can be attached to something/someone the spy is following. This way we can trace the handle even if the invisibility fails when we buy it again. All other items in the set count and work as described.