The mass distribution of halos in one of the N-Cluster Run simulations. We track the evolution of halos with 4 × 10¹⁰ M _⊙ h ⁻¹ ≤ M < 10¹³ M _⊙ h ⁻¹ (red) around filaments that are extracted from the region within 10 virial radii of massive halos of > 10¹⁴ M _⊙ h ⁻¹ (blue). The additional red dotted line at M = 10¹² M _⊙ h ⁻¹ splits our halo sample into massive and less massive ones.