The episode begins with a woman checking her mails and she notices a strange envelope amongst it. A similar envelope is slid down the door of a man ironing his t-shirt. A traffic policewoman also receives a similar mail. The three recipients are ecstatic when they read their mails. Next, Hawkes and Jamie are examining their victim; Maneheim, an ambulance chaser. He was shot from a point blank range and the bullet went through and through his forehead. Hawkes states that the TOD would be around midnight. Mac pulls out the slug from the framed certificate and he is surprised that there are no ballistic striations on it.
There are no signs of forced entry, which suggests that Maneheim knew his killer. He was counsel to 17 bailiffs. Looks like one of the defendants didn’t like the lawyer much!!Meanwhile, Danny and Lindsey watch the news where the cop Rhonda Reynolds tells the media that she received a cashier’s check for a million dollars. News is that about ten people received the same from an anonymous donor. Mauricio Flores, the man we see earlier, talks about his dreams. Jo and Adam wonder about the anonymous donor and the bank does not comment on the identity and refers to him as the Guardian Angel. There is nothing in common in between the recipients other than their new found wealth. Jo makes a note of the names. Jo receives a call; it is about their next victim; Justin Vanderhyden.
Again, no signs of break in! Don educates the team that Justin was a bright kid who now lived on rent. Justin was murdered around ten last night. There are speakers, a mouse pad but no computer. Jo finds a flash drive. Adam points out that the table is covered with some metallic powder. But not totally covered; there is an outline which shows that something was on the table previously. Hakes is examining the metal fragments that he found on Menaheim’s desk and it tests positive for gun powder residue, but there is also some strange mixture and so he isn’t able to identify anything. Lindsey too has nothing on the bullet. Jo is still wondering about the one million dollar checks and she does some digging on Mauricio Flores. Looks like he has some major priors! Sid conducts Justin’s autopsy and pulls out the bullet that was lodged in his pulmonary artery.
The bullet is identical to the one that killed Menaheim. So, what is the connection between a young engineer and an ambulance chaser? Adam hacks into Justin’s password protected phone and finds out that he was at the Triborough Club before he was killed. It is an upscale club where a lot of hip youngsters hang out. Mac asks Jamie and Don to go check the club and he asks Adam to go through Justin’s contacts. Next, Don and Jamie find it strange that not one bartender or any waiter at the club remembers seeing Justin. They then go through the security footage and find Justin entering the club at 7.50 pm. And he walks out with a man a while later. Judging by the looks, it doesn’t look like the lawyer. Adam tells Mac that eh man is Andy Stein and he is the founder of a company called Intellect Fund.
And Justin’s phone says that they were scheduled to meet at the club at 8. Jo and Mac interrogate Stein. Stein appears to be interested in new technologies and there have been a lot of civil complaints against Stein by students whose ideas Stein has stolen. They then tell Stein that Justin was murdered. Stein tells them that he did go to the club to meet Justin; but the kid never showed up. So, after spending an hour in the club, he left by himself. Hawkes finds out what Justin was working on; the same thing that killed him! He found few files on the zip drive that Justin kept in his keychain. He goes through those files and finds out that Justin was printing a 3D gun. Jo finds it hard to believe and Hawkes has a gun printed and ready for demonstration. This explains the lack of striations on both the bullets.
Later, Jo watches the news and she sees that the identity of the mysterious Guardian Angel is being revealed; Richard Kemp. Well, 10 mil is like chum change for Kemp. But Jo thinks that it seems to be some kind of strategy than charity to her. Jo then checks the envelope that was sent to Rhonda Reynolds and runs some test on it. Lindsey is conducting some test on the printed gun and she sees that the gun explodes when the second round is shot. This explains the metal fragments that were found in the lawyer’s office. The gun functioned well and it successfully killed Justin; but the killer did not know that the gun would explode on the second round. So, when the lawyer was killed, the bullet did pass through his head; but the gun exploded as well. Mac asks Lindsey to check every ER record to check if there was any case for something like shrapnel wound.
Lindsey and Danny call all the ERs in the area and Mac runs some tests on the metal fragments found on the lawyer’s desk. Lindsey gets the name of the perp, and so does Mac; Andy Lewis and he has had priors in assault with dangerous weapons. They get an address on Andy’s location and Danny and Mac arrive at a warehouse where they find Andy printing a gun. Andy tries to run but the duo gets hold of him. During the interrogation, we learn that Justin had a meeting scheduled with Andy Stein. But Justin was a little too excited and he arrived early at the club. Andy Stein had not arrived but Andy Lewis had. Justin had never seen Andy Stein before. He finds Andy Lewis sitting on the table and approaches him and tells him about the printable gun.
We further learn that Lewis’ wife was sleeping with her attorney, Menaheim, while Lewis was in jail. She had gone to him for a quick divorce and it turned out to be something else. This made him mad and he wanted to kill her. Lewis tells them that he wanted to calm himself and so he had gone to the club to have a drink. But opportunity presented itself in the form of Justin. Lewis pretended to be Stein and asked Justin to show him the printing. Justin takes him to his lab and prints a gun in front of him. Lewis then uses the gun to kill Justin. He then goes to the lawyer’s office and shoots him; but the gun explodes and he ends up hurting himself. Case Closed. Mac decides to return the printer to the Brooklyn University of Science after Lewis is convicted. But Jo is still stuck with the guardian angel thing.
She feels that Richard Kemp is lying and somebody else gave that money. She knows who but she doesn’t tell Mac. She then goes to meet Sid aka the Guardian Angel. She figured out it was him as she found his finger prints on the envelope. She also knows that those people were not random; they were people who had lost someone they loved and their autopsies were on Sid’s table.
Sid admits. He tells her that he wanted to do something worthwhile with his patent money. These were the cases that stuck with him and so he decided to make their lives better. He then tells Jo that he is diagnosed with cancer and so he wants to do something good before he left this world. He wants to know what happens to the money he left behind. Jo is in tears. The episode ends.