First of all, let's give a shout-out for characters that were M.I.A. this week. 

Following Hawaii Five-0 Season 4 Episode 12 - a big, impressive outing with the parallel stories of Danny and Grover - it was odd not seeing them at all in this week's episode.

But Hawaii Five-0 Episode Season 4 Episode 13 had another major story to tell, a tale of murder close to home. It may have taken 15 years to solve the murder of Chin Ho's father, but this episode deftly dispatched with that heart-wrenching loose end.

With his father's murder unsolved, it had been like having a dark cloud hanging over Chin Ho's life. 

So discovering the connection between his father's murder and the dead body found hanging in the warehouse was like a lightening bolt. He had seen that scorpion tattoo once before, on his brother-in-law Gabriel.

15 years is a long time to grieve and be tortured by the thought that a killr had been roaming free from punishment. But for Chin Ho, an even more painful was the realization that it was his own brother-in-law that had killed his father. 

It was such a senseless act of violence; Gabriel had merely robbed a convenience store to join a gang and Chin Ho's father was just in the way. "Wrong place, wrong time," as Gabriel had finally admitted.

Thus, haunting Chin Ho was the memory that he could have prevented it. Just prior to his dad's death, Gabriel had been arrested for stealing a car and Chin Ho had intervened so Gabriel would not be booked and have a record hanging over his head the rest of his life. 

But that one simple act of kindness set in motion a chain of events that would event tragically for everyone. Gabriel did not learn from his second chance; instead he used it to embark on an even darker path of criminal activity. His proclivity for criminal enterprise spurned him into become a ruthless drug lord, one who would one day return to Hawaii to track down an embezzling employee and leave another dead body in his wake.

Watch Hawaii Five-0 Season 4 Episode 13 Online

The focal point of this episode was not merely Chin Ho's quest for resolution and retribution, but rather the consequences of one bad act. 

Chin Ho's intervention in Gabriel's booking 15 years before had a ripple-effect in both their lives. For Gabriel, it  sent the wrong message about being culpable for his actions. As stated by the IA investigator, "By letting that kid go, you sent a message that he is bullet-proof, and that created a monster."

It had simultaneously cast a shadow over Chin Ho's career. If he had been willing to look the other way and ask for a familial favor all those years ago, who is to say that he has not continue to step over the line and bend the rules when it suited him? 

That is the very question that Internal Affairs was asking. They wanted to prove that Chin Ho was a dirty-cop, one that would follow the rules only when he thought the rules benefited him and ignore them when they did not - especially with millions of dollars of drug cartel money missing.

In his heart, Chin Ho knew he had only tried to do the right thing: to help out a family member. Could he have foreseen that his intervention would be seen as a blanket grant of permission for Gabriel to become a criminal drug lord, or that Gabriel would be the person behind the gun on that fateful day in the convenience store? 

Chin Ho's act had been out of love and desire to protect; unfortunately, Gabriel spurned both. He did not want any charity, expressions of love or to be protected from his own actions. So he took his second chance and continued down the path he had already marked out. Second chances be damned.

Just like Gabriel's actions finally caught up with him, so did Chin Ho's. A cop should not use his power and influence to decide who is prosecuted and who is not when a crime is committed. That abuse of discretion has put I.A. hot on Chin Ho's heels and they are not likely to go away now that they have the scent of a cop gone-wrong. 

Chin Ho may have finally arrested his brother-in-law for the crimes which Gabriel is responsible for, but the suspicion associated with Chin Ho remains. As the I.A. investigator ominously foreshadowed: "You say you're a good cop, but trouble always seems to find you somehow... I'll catch you later."

This episode may have been about putting demons from the past and sins from the past to rest, but it was also about the strength of friendship and family. 

Both Kono and Steve were called in to provide testimony in the I.A. investigation, and both steadfastly stood by Chin Ho. Kono would perhaps do anything to protect her cousin and to protect a fellow officer, but Steve was more level-headed about it as he succinctly told I.A., "Suspecting and proving murder are two different things."

For all those years, Chin Ho may have wondered what Gabriel did that got him that scorpion tattoo right at the time that Chin Ho's father was killed, but linking a tattoo to a murder was impossible at that time. It took another brutal act of murder to finally link Gabriel between the two murders and give them enough evidence to bring him in and officially charge him.

There was a moment there on the rooftop as Chin Ho confronted Gabriel where it looked like he may have wanted to cross the line himself and enact his personal retribution against Gabriel, but in the end, Chin Ho stayed firmly on the right side, as Steve watched knowing his pain and how hard that decision was in that critical moment.

Perhaps knowing that his cousin and Steve were there during the interrogation and even through the investigation and arrest of Gabriel, gave Chin Ho the strength he needed to keep a cooler perspective. 

His cooperation was needed to put the I.A. investigation to bed and keep his badge. He nearly walked out on the investigation, but once he saw that Steve and Kono were there on his behalf and to help in the investigation, he realized he needed to go back and finish it. Their presence reminded him of the value of friendship and family at a time when Chin Ho thought he had none.

It was a beautiful touch to end this raw and emotional episode with the scene of Chin Ho on the beach recalling the day he met his wife. 

Their playful exchange about the surfboard and uniforms reminds us that Chin Ho had a reason for wanting to bend the rules just once - it was because he loved his wife so much that he would do literally anything for her.

Chin Ho may regret having helped Gabriel all those years ago, but he will never regret having helped out his wife the one time it really mattered to her. Love means doing things that may have long-term repercussions that haunt, but it also means you tried to honor those you love by helping them when they ask.  The love between Chin Ho and his wife was just that strong and never-ending.  He would still do anything for her. 

No regrets.

So... is the Internal Affair investigation now over?