The Undertaking

S1 E21: Finding it difficult to mend fences with Tommy and Diggle Oliver instead focuses on crossing another name off the list. While digging through a crooked accountant's laptop Felicity discovers a transaction that could help Oliver find Walter. To reconfirm the lead Oliver gambles that Felicity can be counted on in the field for the first time. In a flashback Malcolm reveals to Robert Queen (guest star JAMEY SHERIDAN) and Frank Chen (guest star CHIN HAN) painful details surrounding his wife's murder and how that shaped his plans for the Glades. Meanwhile Tommy stuns Laurel with the truth.