3週4日目 お急ぎのところ
Development・time・result
接続：Vる／ている／た＋ところへ
At that moment, someone or something happened
注意 / Note：It can almost replace 〜ところに, but へ indicates DIRECTION so it is only suitable when something is approaching: people coming, cars coming, things being delivered. If you don't move, use 〜ところに.
比較 / Compare：Same song: 〜ところに／〜ところを. These models are often mistakenly chosen for each other — carefully read the 接続 and nuances above and then decide.
よく出る形 / Common form：動辞書形／ている／た＋ところへ。The latter is the subject MOVE to: 〜が来た・〜が届いた.
帰ろうとしているところへ、上司が来た。
Just as I was about to leave, my superiors arrived.
寝ているところへ宅配便が届いた。
While I was sleeping, the delivery arrived.
店を閉めようとしているところへ、常連客が入ってきた。
Just as he was about to close the store, a regular customer walked in.