The origin of pre-transition disks, disks around young stars that consist of an outer and an inner dust ring, have puzzled researchers for decades. The inner rings seem to live very long, even though scientists did not think this could be possible. Our recent paper, published in Astronomy & Astrophysics, proposes a solution to this puzzle: the outer ring constantly supplies the inner ring, but it does so without being seen: the material is transported in only few large grains that are not easily detected. Therefore the regions between the rings do appear to be empty. Once the dust particles have reached the hot inner regions close to the star, they loose the water ice that binds them together and consequently, they break up into many small pieces. It is these small pieces we see close to the star as a second, inner hot ring of dust. Our paper was featured on Astronomie.nl (Dutch).