There's no getting around it: Aeschylus's Agamemnon is a challenging play – even though its plot is about as simple as they come. Part of this simply has to do with cultural differences between our time and that of the Ancient Greeks; this is the same basic challenge posed by any work from classical antiquity. More fundamentally, however, this play is challenging because it doesn't pull any punches in dealing with extremely complex and profound themes of Justice, Free Will, Language, and others; in fact, it raises so many questions that it took Aeschylus two more plays to try to get them under some sort of control, though even the Eumenides (the third part of the Oresteia trilogy) doesn't tie everything up in a neat little package. To top it all off, the language of the play is extremely challenging, especially in the passages sung by the Chorus, which are stuffed full of a disorienting array of metaphors and mixed metaphors, constantly shifting into one another like the colors of a kaleidoscope.
We're not dwelling on the challenges of this play to discourage you; far from it – this sheer wealth of poetic and intellectual energy is what makes Agamemnon totally awesome. What we are saying is that, when you are scaling this mountain, don't be surprised if you find yourself feeling dizzy. Once you make it to the top, however, you'll never forget the view.