▁order ▁of ▁ 1 0 ▁episodes . ▁The ▁season ▁premier ed ▁on ▁January ▁ 8 , ▁ 2 0 2 0 ▁and ▁concluded ▁on ▁February ▁ 1 9 , ▁ 2 0 2 0 , ▁with ▁a ▁two - hour ▁series ▁finale . ▁ ▁Cast ▁The ▁entire ▁main ▁cast ▁from ▁the ▁previous ▁season ▁returned . ▁ ▁Main ▁cast ▁▁▁ ▁Joe ▁M ante g na ▁as ▁David ▁Ros si ▁ ▁Matthew ▁Gray ▁G ub ler ▁as ▁Dr . ▁Sp encer ▁Re id ▁▁ ▁A . ▁J . ▁Cook ▁as ▁Jenn ifer ▁" J J " ▁J are au ▁▁ ▁K irst en ▁V angs ness ▁as ▁Pen el ope ▁Gar cia ▁ ▁A ish a ▁Ty ler ▁as ▁Dr . ▁T ara ▁Lewis ▁ ▁Daniel ▁Hen ney ▁as ▁Matt ▁Sim m ons ▁ ▁Adam ▁Rod rig uez ▁as ▁Luke ▁Al vez ▁ ▁P aget ▁B rew ster ▁as ▁Em ily ▁Pr ent iss ▁ ▁Special ▁Gu est ▁Stars ▁▁ ▁Jane ▁Lyn ch ▁as ▁D iana ▁Re id ▁ ▁A ubre y ▁Pla za ▁as ▁Cat ▁Adams ▁ ▁Jay ne ▁At kin son ▁as ▁Er in ▁Stra uss ▁ ▁C . ▁Thomas ▁How ell ▁as ▁George ▁F oy et ▁ ▁Rec urr ing ▁cast ▁ ▁Josh ▁Stewart ▁as ▁William ▁La Mont agne ▁Jr . ▁ ▁M ek hai ▁Anders en ▁as ▁Henry ▁La Mont agne ▁ ▁Kelly ▁F ry e ▁as ▁Krist y ▁Sim m ons ▁ ▁Dec lan ▁Wh ale y ▁as ▁David ▁Sim m ons ▁ ▁Stephen ▁Bishop ▁as ▁Andrew ▁M endo za