One of the things I like about having a narrator, is that she can ask questions of the reader, or make assumptions about the things that they might like to know. This allows for quite a few indirect questions, such as the one below. First, lets begin with a translation. There are two words here that I needed to look up. peniculus - paintbrush - wasn't hard to find. I found discus pigmentarius - palette - in a Latin/German dictionary of modern vocabulary.
The page reads; Firstly, perhaps you are asking why Marcellus is holding a paintbrush and palette.
If this was a direct question - Why is Marcus holding... - the Latin would be cur Marcus tenet? But when that question is imbedded into a longer sentence as an indirect question, the verb changes ever so slightly - quaeris cur Marcellus teneat.