Jennifer Lopez starts the chain of kindness by celebrating an inspiring young fan and her mother.

Hospital staff helped Kevin Hart recover from a serious car accident. He's back to return the favor -- and to encourage the staff to do the same.

Nick Jonas surprises longtime fan and mental health awareness advocate Carla, who in turn repays the kindness with a visit to her old high school drama teacher.

Kristen Bell shows her appreciation for a pre-school teacher who taught her a lot about motherhood.

Before he lit up the NFL, Aaron Rodgers had a mentor who helped him believe he could get there. Now he's ready to return the favor.

Yara Shahidi kicks off this chain by honoring the legacy of childhood friend Cameron Boyce.

Tracy Morgan overwhelms an inspiring gym owner. Later, this community leader gets to pay it forward with an old friend.

Basketball star Anthony Davis thanks a Los Angeles local graffiti artist for welcoming him to the city when he was traded to the Lakers.

Karlie Kloss surprises a former student of her Kode With Klossy camp. And this proud pupil has another mentor she'd like to thank.

When Gabriel Iglesias was in high school, speech teacher June helped him overcome some serious issues. Now she's at a taping of his show - and in for a big surprise.

Vanessa Hudgens starts a chain of giving with an unbelievable gift for a local addiction specialist primarily helping those in the Black, Latinx, & LGBTQ+ communities.

Chris Rock begins a chain of gratitude by donating to a local Downtown Los Angeles pastor who is helping the homeless community during the pandemic.

Mark Cuban gets inspired by a person courageous enough to ask for help and uses the opportunity to start a chain of gratitude.

Lana Condor surprises her former trainer who has been fighting to keep his gym open during the pandemic by giving him an amazing gift.

Hasan Minhaj begins a giving frenzy with a gift to the leader of a community advocacy group for Black Americans in South Central Los Angeles.

Matthew McConaughey begins a chain of gratitude by donating money to someone who has spent his life bringing art lessons to underprivileged communities in Los Angeles.

Normani gets the chance to thank her former dance teacher and mentor with a life-changing gift.

Emma Chamberlain starts a “chain of love” by helping a high school senior that has strived to support people struggling both mentally and physically during the pandemic.

Liam Payne is known for his voice, but his big heart takes over on this episode when he surprises a local food bank owner with a donation she’ll never forget.

Becky G reconnects with a teacher helping the community and surprises her with an A+ gift.