The Brothers Grim Trivia Quiz

Answer: Ryan's brother, Trey Atwood

Trey Atwood appeared in the pilot episode as the mastermind behind the car theft that would send Ryan to the juvenile detention facility where he meets Sandy. Since Trey (an adult) had priors and a gun on his person, he was sent to prison. Ryan and Marissa visited him in prison in the first season Thanksgiving episode "The Homecoming." In those episodes, Bradley Stryker portrayed Trey. Starting with "The Brothers Grim," Stryker was replaced by Logan Marshall-Green, who would go on to appear in 8 additional episodes. Prior to "The O.C.", Marshall-Green appeared in six episodes of "24." He also had a role in the 2005 WWII film "The Great Raid."

Answer: Summer's ex, Zach Stevens

Michael Cassidy returned as Zach Stevens, last seen in the 14th episode of the 2nd season, "The Rainy Day Women." In that episode, Summer left Zach at the airport on their way to Italy for his sister's wedding when she realized that she wanted to be with Seth instead.
Michael Cassidy made the most guest appearances as a non-family member on "The O.C." with 19 episodes. All "guest stars" with more appearances were, at some point, billed as series regulars (this includes Chris Carmack as Luke Ward and Willa Holland as Kaitlin Cooper). Michael Nouri (Summer's father, Dr. Neil Roberts) also had 19 episodes. The two Michaels were followed by Samaire Armstrong (Seth's ex-girlfriend, Anna Stern) with 15 episode appearances.
Michael Cassidy starred in the 2006 film "Zoom" with Tim Allen and would later appear with Taylor Handley (first season's Oliver Trast) in TV's "Hidden Palms."

Answer: Chicken Parmesan

Sandy enters the kitchen, calling out that it's dinnertime and asking Kirsten how she feels about "Chicken Parm." He doesn't realize that she's on the telephone and when she blurts out, "That is simply unacceptable," Sandy assumes she's talking about the food. It turns out that she's talking to Carter Buckley, the company magazine's editor.

Answer: Vespa

Marissa and Summer's first scene of the episode took place at school, where they were discussing Ryan's upcoming reunion with his brother. Through the window, they saw someone drive up on a red Vespa. When he removed his helmet, they realized it was Zach and Summer started having a "panic spiral."
A bit of interesting trivia, if you have access to the season on DVD, there is a blooper of this scene, with Rachel Bilson having an uncontrollable laughing fit and Michael Cassidy saying his lines in a very goofy manner.

Answer: naked

As Kirsten and Carter were cutting a video for the launch of their magazine, Julie entered the office to speak with Kirsten. Julie then told Kirsten that she "made a mistake, Kiki. A naked mistake." She then proceeded to tell Kirsten about the video for which she was being blackmailed. Kirsten's advice was to tell Caleb.

Answer: Francesca

Seth ran into Zach by the lockers at school and welcomed Zach back to Newport, saying that "people never leave and come back (a meta reference to other guest stars such as Oliver and Lindsay). When Seth started to apologize for the Summer situation, Zach cut him off and told him that he met someone in Italy but not to tell Summer.
We find out later that Zach made up the girlfriend because he didn't want Summer to know how bad she hurt him nor did he want things to be tense between him, Summer and Seth.

Answer: crawfish

Julie was trying to get on Caleb's good side by fixing his favorite meal for his lunch. She claimed that she hadn't spent enough time with him and wanted to catch up on events. As she went through a list of topics, such as fixing the showerhead and replacing the gardener, she slipped in the subject of her adult film and the need for the blackmail money.

She added on at the end that she'd also like to redo the kitchen. Caleb agreed to pay the money, saying that her dignity was at stake and he figured that was worth at least half of a million dollars.

Answer: False

Caleb showed up at Lance's motel room with a briefcase of money. He handed the briefcase to Lance in return for the tape, asking if it was the only copy (to which Lance answered that it was). Once the exchange was made, a knock at the door revealed that Caleb had brought two men to assure that Lance didn't keep the briefcase. Caleb left the motel with his money and the tape.

Answer: False

While Trey, Ryan and Marissa were shopping for new clothes for Trey, they looked at a watch but didn't end up buying it. On their way out of the store, a manager told Trey that they would need to search his bag since they'd seen him handling the watch earlier. Trey became defensive, dumping the bag's contents on the floor and kicking over a clothing rack. Later, Ryan stopped by the pool house to see if Trey wanted to hang out.

While joking around, he started throwing clothes and uncovered the watch.

When Ryan accused Trey of stealing it, Trey showed him the receipt and said he's bought it for Ryan as a gift of thanks. Since Ryan had immediately assumed the worst, Trey was upset and stormed out.

Answer: Lance

Sporting a black eye, Lance decided that since the deal with Caleb didn't turn out the way he had planned, he would go forward with releasing the tape (he obviously lied about Caleb having the only copy). He showed up at the party dressed as a waiter and replaced the launch video with the adult film.

The tape was played on big screen in front of Julie's friends and the high society of Newport Beach. Luckily, Marissa had already left for Chino with Ryan so she was never made aware of the scandal.