Hawaii Five-0's Danny Williams isn't finished dealing with his little brother's death.

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The Five-0 detective arrived in Columbia to trade $18.5 million for Matt's life, only to discover that Reyes had already dispatched with his brother. Danno's (Scott Caan) retribution was swift and deadly, making the entire mission traumatic enough haunt him for some time (see video below).

By time the series' Halloween episode, "Ho'omā'ike (Unmasked)," roles around, Danny won't be able to put off dealing with he fallout any longer.

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"There is a very emo scene in episode 506 that deals with it," teased showrunner Peter Lenkov on Saturday.

If fans have any lingering suspicions about Matt's fate, Lenkov assures viewers that the "no body, no death" theory definitely does not apply in this situation.

"Yes, [Matt is as] dead as a doornail (as they say)," the EP confirmed.

Meanwhile, Chin (Daniel Dae Kim) will have to deal with the $5.5 million he borrowed from Gabriel Waincroft (Christopher Sean) and the possibility that it could come back to bite him with Internal Affairs.

Find out more when Hawaii Five-0 airs Fridays at 9 p.m. ET on CBS.

Tags: Hawaii Five-O television CBS