We have received a pair of new problems involving plasmonic spheres and their reference solutions in the time domain. The main focus of SOLBOX-04, which was submitted by Ismail E. Uysal, H. Arda Olku, and Hakan BagcI, is computing scattered fields from gold spheres. The challenge is incorporating plasmonic effects that dominate at optical frequencies. In addition to negative permittivity values to be used in the implementations, the submitters had to deal with the highly dispersive properties of the structures in the time domain. Reference solutions were also provided along with the descriptions of the problems. Mie-series solutions were also available for one of them, demonstrating the accuracy of their approach. We are looking forward to receiving alternative solutions for these new, challenging problems, as well as for the previous submissions in the earlier issues (SOLBOX-Ol, SOLBOX-02, and SOLBOX-03).