The episode begins with Holmes playing his memory game and Watson wants to finish the talk they were having last night. She wants him to be serious about finding a sponsor as she will be with him only for a few more weeks. He agrees. Next, we see a group of web designers discussing about a new client. They hear a beeping sound coming from the vent. They think that the maintenance guy must have left his phone inside. We see that it is a bomb ad moments later, it explodes. Gregson, Bell and Holmes arrive at the site along with the team. Gregson tells Holmes that 2 were killed and 11 injured.
Holmes finds some packing paper lying around and this was used in the bomb. He then finds a motherboard of a pager. He feels that could be the part of the bombs detonator and since it isn’t too damaged, it can be traced. It would take around 2-3 hours for the results to be back and so Watson manages to get Holmes meet one of the sponsors, Adrian. But after talking to him for barely 2 minutes, Holmes decides he doesn’t like Adrian. There was a number pulled out of the device which was traced to a Rennie Jacobs who has served time for burning down his own house for an insurance scheme. Jacobs tells them that he was trying to call a deli and he must have misdialed. Holmes confirms that he is telling the truth. Maybe; but Gregson doesn’t want to cut him loose.
Later, as the bomb squad is explaining the scene to Gregson, Holmes points out to the picture of the battery and tells them that the bomb is four years old. He knows about the company and its new logo and this one is four years old. He then checks the newspaper shreds and Watson points out that it is from 2008. This means that Jacobs is innocent as he was in prison four years ago. So, Jacobs is a man who set it off accidentally in 2012 and now they need to find the guy who intended to set it off in 2008. Next, Holmes and Watson are in Van Owen which was founded in ’94. And this firm is adept in solving image crisis of the corporate variety.
And looking at the date of the bomb and the location of where the bomb exploded, Holmes deduces that Van Owen or one of its employees was the target as the place that was bombed was the old office base for Van Owen. They meet with Heather Vanowen and the CFO and they tell Holmes that they received some threatening mails from ELM. They are curious as to why didn’t the bomb go off. Holmes tells her that since the detonator was a pager, four years ago there were no signal towers around in the area and so the call wouldn’t go through and in 2010 there was a tower that was built just three blocks away. Hence the call went through this time.
And judging by the climatic conditions of the office, it looked like it did not require too much servicing and so, the bomb went unnoticed. Holmes goes through the letters ad finds out that ELM isn’t really a company but it is posing as one. At the AA meeting, Holmes decides that he wants Alfredo to be his sponsor. Alfredo is trying to stay clean and he can steal any car in the city. At home, he tells Watson that there is a phrase that has been repeated in five of the seven letters and that he has heard this phrase before. He then recollects that it was a talk show that he heard it on and the man is Edgar Knowles. They need to find out if he is the one who wrote those threatening letters. Bell talks to Knowles and he tells Bell that he is not an eco-terrorist and that he did not make a bomb.
Holmes arrives and tells him that he had managed to get Knowles’ prints off a button from the elevator and it matches to the prints that were found in an explosion of 2005. Knowles admits to five bombings and the writing of the threatening letters. But he did not plant this bomb. Holmes is now trying to create a bomb with tennis balls and few chemical components. He tells Watson that Knowles had admitted to have set off five nitrate bombs but the smell on the explosion site did not smell pungent. He tells her that the bomb was made with potassium chlorate. At the station, Holmes puts together the piece of paper from October 13th 2008 that was used to pack the bomb and there was an indentation that he noticed; it said NOVACAINE and the handwriting does not match Knowles’.
Gregson still likes Knowles as a suspect. Holmes wants Gregson to subpoena the personnel files from Van Owen; but he tells Holmes to take it u with them. Watson and Alfredo are waiting for Holmes and Holmes messages Watson saying that he is at Van Owens and cannot make it. Watson then talks to Alfredo and learns that he is a good person and can make a great sponsor as Alfredo had a great sponsor for him and he taught Alfredo everything. He has wanted to be a sponsor for a while, but nobody asked. Watson is pleased with Alfredo. Holmes is going through the papers of the company and he notices that a guy named Pradeep Singh who had shown significant rise in a year and a half, had an argument with the CFO just before he left. The CFO tells him that Singh snapped and told him that he would be sorry if he wouldn’t give him his fourth raise.
He then disappeared and never came back. Holmes and Watson go to Pradeep Singh’s house and his wife Himali tells him that she did not hear from him after he left. Holmes is curious when he looks at the wall and he asks her if there was any work done on the walls as he could smell mold. He later asks the women to wait at the backyard and he inspects the wall. Later, he comes out and tells Watson his theory. He feels that Pradeep Singh’s body is in that wall. He is right. Gregson tells Holmes that Himali was in Mumbai and she came back only after she learned that Pradeep was missing. This means that the killer knew she wasn’t home. Holmes thinks that Pradeep did not have anything to do with the bomb. He shows them a picture from 2008 where Pradeep is on his desk and it is right next to the vent in which the bomb was planted.
This means he was the first one to be blown off by the explosive. Moreover he did not miss a single day of work until he went missing. So, someone wanted Pradeep dead. Bell tells them that Pradeep was killed by a gunshot wound. There is a key found on him and it is a safety deposit box key. The check the box and they find a video tape. It is a sex tape from the time where Heather was a prostitute and was trying to supplement her income to start a new company. Years later, Pradeep joined Van Owen and found out that his boss was the prostitute he once slept with. Moreover, the handwriting of the word NOVACAINE is a match with the one on the consent form she just filled for them.
She was the one who planted the bomb and then when it did not explode she shot him and then walled him in his own house. And then went looking for a new office. Case Closed. Holmes had told Alfredo that he did not want him as a sponsor. Watson knows that he is dreading the day she would walk out of his life. Alfredo arrives at Holmes’ house with a challenge. He wants him to beat the security systems of a latest car that is not yet in the market. Holmes knows that Watson and Alfredo are doing this so that Holmes warms up to him. Anyway, Holmes takes up the challenge. The episode ends.