Defense in Edwards Case to Keep Heat on Former Aide John Edwards and his daughter Cate arrived Wednesday for the third day of his corruption trial. The day focused on a cross-examination of Mr. Edwards's former aide, Andrew Young. GREENSBORO, N.C. - Andrew Young, the onetime top campaign aide and close friend of former Senator John Edwards, will return to the stand on Thursday morning, and Mr. Edwards's defense lawyers are expected to continue their withering cross-examination of him as part of Mr. Edwards's federal corruption trial. Mr. Young, the chief witness for the prosecution, has spent much of the week describing the expensive and elaborate lengths to which Mr. Edwards went to spend time with Rielle Hunter, the woman with whom he had an affair that produced a child and to hide the relationship from his wife and the public. On Wednesday, after spending more than two days responding to the gentle questioning of government prosecutors, Mr. Young received a rough introduction to Abbe Lowell, a highly sought-after criminal defense lawyer, who spent the afternoon looking for opportunities to pick Mr. Young apart. Mr. Lowell called Mr. Young a liar and accused him of seeking to make himself indispensible to Mr. Edwards and his family so that Mr. Young could ride alongside as Mr. Edwards - a two-time presidential candidate - reached for the White House. That plan, which included Mr. Young claiming paternity of Mr. Edwards's illegitimate child in an effort to avoid a scandal, was financed by nearly $1 million from two wealthy Edwards supporters. Whether that money was used to influence Mr. Edwards's run for the 2008 Democratic presidential nomination, or was merely an effort to help him hide the affair from his wife, is at the heart of the six charges he faces. If convicted on all counts, Mr. Edwards could be sentenced to 30 years in prison and $1.5 million in fines. Although Mr. Edwards had spent much of the previous two days at his trial speaking quietly to his lawyers at the defense table, writing notes, or sitting back in his chair looking down, he stared intently at Mr. Young on Wednesday when it was his former aide's turn under fire. After court, Mr. Edwards walked outside and for the first time made a comment loud enough for the TV cameras that line the walkway to pick up. "Oh, the sun is out in more ways than one," he said Mr. Young, on the other hand, has presented a less comfortable mien. He has walked stiffly in and out of court each day, and has made a point of not looking around the courtroom while on the stand. Instead, he has peered straight ahead when not focused on pieces of evidence he is presented to study. Throughout Wednesday afternoon, Mr. Lowell homed in on inaccuracies in a book Mr. Young wrote about his time with Mr. Edwards, from Mr. Young's national media appearances, and from a paid speech made by Mr. Young, challenging Mr. Young over even the smallest contradiction. Did he leave his job with Mr. Edwards's Senate office because he was unhappy in Washington or because he was bad at it? Did he first meet Ms. Hunter at an airport, as he asserted in earlier testimony, or at a hotel, or perhaps at a Dave Matthews concert? And how much did he really know about the tense triangle involving Ms. Hunter, Mr. Edwards, and his wife, Elizabeth Edwards, who died of breast cancer in 2010? Didn't you purposely exaggerate so many of these stories to tell a better story about yourself? Mr. Lowell asked. Mr. Young, who has been granted immunity in exchange for testifying, turned from a cooperative, if not subdued, witness for the prosecution into one whose refrains were characterized by "I don't recall," and "I would be guessing, sir." By the end of the day, Mr. Lowell suggested that the Edwards-Young relationship was akin to a love affair, and that Mr. Young was the political version of a scorned lover. According to Mr. Lowell, Mr. Young had ingratiated himself into Mr. Edwards's life for personal gain and prestige. And then Mr. Edwards had turned his back on him. You really hate him, don't you? "I have mixed feelings," Mr. Young responded. Earlier in the week, Mr. Young described to the court how he and Mr. Edwards had found money from two wealthy campaign donors to financially support Ms. Hunter so their affair could continue and how the strains of the cover-up led the relationship between Mr. Young and Mr. Edwards to crumble.