Protect Samos in Haven Forest was a mission in Jak II. The young Samos Hagai needed the Life Seed to gain his sage powers, but soon after Jak arrived to deliver it they were attacked by the Krimzon Guard.
There will be two air trains dropping off numerous guards, and several hover guards who will harass you. You will have to protect the defenseless Samos from the KG (who will only be armed with tasers) for a couple of minutes. They only appear from the two bridges although this does force you to divide your attention and go back and forth. Don't go down either bridge as you won't be back in time to defend Samos from the guards coming up the other one.